How about adding a feature that allows the required water volumes to also be displayed in inches? I do BIAB batches in a big kettle and don't want an additional "thing", like a sightglass, to get in the way. Thus, I've been measuring volumes in inches with a nice SS yardstick. When the mash step says the recipe calls for 15.5 gallons, it would show as "start with 15.5 gallons (xxqts, xx.x inches, xx centimeters)". This could be pulled from your equipment profile if you could enter kettle volume and height. Other (obviously inferior!) BIAB calculators do this (eg priceless brewing).