Just killed Lich, while in Age 2. Looking at next advancement "Mighty Stroganoff". Went to make Mushroom Stew which is 3 mushrooms a bowl, and Unfamiliar Item (which I guessed was milk) Milked a cow, and of course it drops the bucket, but with a full quick bar, it goes to inventory. I put that, the bowl, and mushrooms in cauldron for it only to return with Mushroom Stew, and 2 buckets in cauldron. I was then able to repeat this a second time

This doesn't seem like a BuildCraft issue in the slightest bit.

I‘m honestly curious. You seem to be playing SevTech: Ages. That pack has its own issue tracker on GitHub.
How do you even get to this issue tracker?

please report this on the sevtech issue tracker: https://github.com/Darkosto/SevTech-Ages/issues

people seem to not be reading the startup notification of BuilCraft being in alpha as 'report any and all issues here' even though it only relates to BuildCraft

My mistake, the report bug link was on separate line, so I thought this was correct area for pack, thanks, sorry