No, not quite.
We typically use BeerSmith, or an application like it, along with the information that we know about our system (actual volumes, boil-off rate, etc). We plug that info into BeerSmith, then we put together a recipe using BeerSmith, which does alot of the math for us - it'll calculate, based on our desired sparging method, just how much water we need to use to get the correct volume of pre-boil wort at the correct pre-boil gravity, that'd throw off your gravity. There's no boiling down to a volume before starting the timer - you sparge to the correct volume and gravity, period.
Now this is not to say there's not a learning curve to using BeerSmith, just like there's a learning curve to any other tool. I had been using BrewTarget for a while, for instance. I picked up a copy of BeerSmith last summer, found that it had a lot more functions and it was more appealing to me, so I decided to make the switch. It was about 4 batches before I was dialed in to the point where I was able to line up my results to what BeerSmith was predicting, because there are an awful lot of parameters you need to figure out and fine tune...