Modified BIAB Question

Hello:

I just purchased a 15 gallon converted Keggle with false-bottom and spigot and I already have an 8 gallon aluminum pot that I've used to BIAB with so far. I'm wondering if it's possible to do some type of modified all-grain method where I use the keggle as a full volume mashtun and then transfer it to the 8 gal of boil or should I just do a full volume BIAB in the new pot? Also if anyone has Beersmith and can recommend what my equipment profile would be I'd appreciate it.

This will only be a temporary setup because I'll be acquiring another keggle soon and and building a brew stand.

You could do what I just tried... mash in your keggle and boil in your 8 gallon.
You'll need a vessel to drain into though.
Mash at 1.25-1.5 gallons per lb.
Drain off the first runnings, note how much grain absorption there was, sparge to gather your boil volume.
The only things you would need is a mesh or false bottom for your keggle. and a collection vessel.
Once you sparge and gather the runnings, boil in the 8 gallon.

Hello, the keggle has a false bottom already (mesh) for that exact purpose ^^. Can I drain off into my 8 gallon pot for boiling? Is that what you mean by collection vessel??

Yes, but if you want to sparge, you'll need your second pot to heat the sparge water.
What I was suggesting is draining into a bucket or something, heat sparge water in your second kettle, add that to the tun as sparge water, drain (add) that running to your wort already collected, pour all that back into the boil pot for the boil process.

Thanks for the info, I'll try it on a winter warmer that I'm about to brew.