Good news, this one is now live!
When you start a stock take you can choose exactly which part of your stock it covers. Tick a whole type to count all of it, or tick just some of its sub-types to narrow it, so a count of only your hops and grain leaves your finings, yeast and everything else completely untouched. Products work the same way, by container type.
One thing worth knowing: a stock take still treats anything it covers but doesn’t see as zero, so count all of whatever you have chosen to include. There’s a section on this in the guide: Breww | Stock takes | Help guides
Full details of this and the rest of the update here: Stock takes just got much easier to run