What is a difference in 4 gallons filled keg and keg filled with 5 gallons and 1 gallon removed through the tap couple weeks later? In both cases there is CO2 above the beer.
I only store (freeze) yeast from a starter I make before brewing. Never yeast from a slurry after making the beer.
I just make 2x bigger starter when I need to store. Stored yeast is always clean.
I am pretty happy with BeerSmith I use for many years. This is how it shows my last beer. I used less water then recommended. Only 8.25 gallons. Measured OG came quite close. What really counts is if the beer tastes good :)
One has to think about heating the pot, too. I forgot last week to put in a dummy bottom and burned a hole in the bag. A small problem :) Got a new one ASAP.
I use Avantco 3.5kW induction burner, so the pot must work with it. The way I used to test compatibility was to use a fridge magnet. If...
I use 60 qt pot for 5.5 gallon batches. One needs to start with ~8 gallon of water and ~10lb of grains for average batch. Grains take extra space in the kettle.
With expired dry yeast I always make a starter. With last pack, even fresh, I make 2qt starter. 1qt goes to the beer, 2nd qt I use to make 5-6x 15ml tubes for my frozen yeast bank. I do that like described in Freezing Yeast
This is my local Wiki:
My yeast lab is located on kitchen table.
https://www.homebrewnotes.com/making-a-frozen-stock-yeast-bank/
https://suigenerisbrewing.com/index.php/2015/11/28/easy-home-yeast-banking-and-a-video/
https://www.homebrewtalk.com/threads/maintaining-a-healthy-yeast-bank-long-term.678997/
It takes me less then 10 minutes to move 5 gallon batch of beer from the fermenter to 5 gallon keg. My kegerator has 3 taps and can hold 4 kegs, so the 4th keg lagers no matter what type of beer it holds. When the keg is on tap it is already carbonated.
I use both. Beer quality the same. Grains are cheaper when buying 55lb bag but take longer to make the wort. BIAB only in my case.
Home grown hops in a bag, pellets no.
I do use. In addition 1 campden tablet per batch.
I use a wort chiller.
I love my TILT. I can enter OG and FG into my BeerSmith...
I have most of them in my frozen yeast bank. All are very good. So far I am up to the second generation. The beers are best when keg is almost empty. 2-3 months after kegging.