To start, I do shoot for a consistent package volume of 6 gallons for each and every batch. If I change the batch size to 6.75 as you suggest do I then just "assume" the losses as a mental note that is not directly referenced in the software anywhere?
Yes, but you can put the note about losses in the recipe notes, the recipe name, or anywhere else that makes sense. The nice thing is that knowing the kettle batch size is much more useful for sharing and equip/ingredient changes. Any post-boil volume losses are virtually 100% finished wort, so when sharing or making adjustments, it is much easier to figure out what batch size to scale to (always checking the 'keep numbers the same' box). There is some extra work to be done using this method, but there are also significant work saving and simplification.
If you haven't been doing the proper calcs that BeerSmith expects you to for the normal way, it may seem like a lot of extra work, but if that is how you have been doing things, your numbers can't have been correct. The benefit to the user depends on how he wants to use BeerSmith. If you want to share/import recipes more easily, make efficiency and trub loss adjustments without having to do extra calcs, adjust efficiency based on grain bills; then the this new method is much easier.
When scaling for new changes, creating new recipes, or simply increasing batch size, it is always best to pick a 'base' version of a recipe that has turned out/hit the numbers well. Make a copy, rename (I put batch size and trub loss in the name), and then scale the copy.
Then, if for example I brew a beer that historically has absorbed an additional .25g due to hop additions I re-scale the recipe to a 7g batch size to account for the additional loss?
'Historically' is a little confusing, because you would/should have corrected losses for that if it has occurred many times previously, but I think you are describing the process correctly. After brewing a recipe, you check your losses and kettle eff, and adjust the recipe for the next time. The knowledge can also be used to adjust losses/eff to other recipes if you know what caused the losses/eff- hops, grain bill, new equip losses, etc. This is standard BeerSmith procedure. The difference is that the new method is much easier to adjust things per recipe, and all you have to do is put the actual numbers you measure into BeerSmith. There is no need to do the additional 'to the fermenter' efficiency calculation by hand/externally anytime either mash eff, trub loss, hop loss, or equip loss changes.
Even more convenient is you can very easily proactively compensate for ingredient losses like when creating a recipe for an extra hoppy beer, or deciding to switch a recipe from pellet to leaf hops. Before brewing you just predictively figure out the hop absorption/loss (there are several calculators for this), and scale the recipe by that amount. It gets a bit weird here, because since you scale the recipe, the hops increase, so you get more losses. The way to cheat, is to just increase your losses a bit the first time you scale to account for the increased hops. Checking the new hop absorption value compared to your guess will show you if you need to scale again. As long as you are not under, or over by a large amount, most just call it good and don't try to get it exact.
This sounds a little tedious, but is much easier than the old way of using the trub loss field. Doing that, you would have had to do these same calcs, as well as a bunch of extra calcs to get your efficiency number correct. In the BeerSmith forum, I suggested adding a hop loss tool that would do the compensation for you. I was beaten down, and told it wasn't necessary- even after I explained how the trub/hop loss increase causes a feedback loop that causes more hop loss, and requires more scaling.
Are you suggesting then that when I go to brew my next recipe, not a repeat, to make these changes prior to design, brew the beer and evaluate the efficiency and use that as my new efficiency number. Then, I can go back to a previous recipe and re-scale to meet these new numbers based on the revised batch size and efficiency number. the software will then perform the the adjustments to meet the edited equipment profile?
Yes. If you switch to this method, there should be no difference in the results you would have gotten the old way- nothing changes in the results of the math in BeerSmith. Recipes will not automatically change, so any recipe you want to brew using the new method, you would need to use the new eqipment profile that has no trub losses, your 'kettle/mash' eff as 'tot/brewhouse' eff, and scale the volume for any losses.
The only thing you need is a good current mash eff number, or a good 'tot eff' number that you can get your current 'mash eff' from. If you have a good idea of your current 'mash eff', which you should know even if using BeerSmith the old way, then you can use that directly. If you don't know your mash eff, but have a current 'tot eff' number that has worked for you, the mash eff can be determined from that. BeerSmith even calcs it automatically as 'est mash eff' in the profile. For a known good 'tot eff' number, the 'est mash eff' (since that is your actual mash eff) is the eff number you would put in 'brewhouse/tot eff' if you use the new way of zeroing out trub losses.
After brewing any recipe, new or repeat, you should check your numbers to see if you hit them. You can use this information to adjust all recipes if it is a consistent effect, or by recipe if it is related to ingredients. Mash eff can change for different grain bills, so to get even better estimates you can tune mash efficiency by beer style/grain bill. You just start with a 'base' eff number, and adjust it based on results from similar brews.
In follow: i will assume if the above is correct the OG/FG issue questioned would then be corrected as well as the re-scaled recipe would account for this based upon the adjusted percentage and batch size?
Yes, when you scale the original recipe (using the scale tool and checking the 'keep numbers the same' box) to increase batch size by your losses (after you change trub loss to 0, and put your 'mash eff' in as the 'tot/brewhouse' value); then the brewday numbers- water vols, grain bill, hops, OG, SRM, IBU, vol to fermenter, etc. will all be exactly the same as the original recipe. For future loss adjustments to the recipe/equip, you would simply scale the batch the same way.
The only change being made to how BeerSmith expects you to use it, is to account for losses in the 'batch size', and use 'kettle/mash' eff as 'brewhouse/tot" eff (which is the common definition anyway).
There is a box next to 'equipment' in the recipe creator that allows you to change the only the local copy that the recipes keeps. Use this for per recipe changes. When you want to change all future brews, create a new equip profile (copy, rename).
In short, am I to assume that the ultimate benefit of this procedure and correction in the set up enables a user to simply scale a recipe to account for possible changes in experienced losses on a batch by batch basis without having to make any adjustments to the equipment profile?
Yes, much easier to tune on a recipe by recipe basis, but also much easier when just doing normal iterative system tuning for mash eff changes. There is no need to do all the extra calcs required to get the old style 'to the fermenter' eff number. Sharing recipes, both importing and exporting, is also much more straightforward.
Also, there is a math flaw that causes small errors when doing it the old way due to trub loss being included twice in the calculations. In reality it is a very small error, but some people have a disease that won't tolerate it.