I took the initiative to add in digestive enzymes mechanic for the engulfment revamp (not the whole enzymes system) and now have the basic functionality working: select lysosome → modify → select enzyme (lipase, chitinase, cellulase) → chitinase and cellulase unlocks walled cells consumption. Try it out from this commit.
Since calcium carbonate and silica membrane have no counter enzymes, I’m not sure whether these two should be digestible or not with the way how digestion in the engulfment revamp works. It’s either in or out (health is not taken into account) and if they are still affected by lipase they’ll have no advantage over predator’s engulfment.