Can't you at least give us the maximum stack size instead?

I mean, I guess I could.. although in that case, you would be losing some amount of the base ingredients, and I'd have to manually check what the stack sizes of said problem items are... which can be changed by other mods anyways... and the items that can't be uncrafted are already few in number...

Seems unnecessary. Unless you're uncrafting satellites or something, you would never really run into this problem, especially when the main point of the recyclers is to uncraft items which have become obsolesced.

2 months later, I decided to add a safety toggle for this. Either Factorio changed to allow this, or maybe I didn't test enough in the first place, but with the safety toggle off, items which exceed the stack limits of their ingredients will recycle to the stack limit. I distinctly remember items like that simply getting stuck in the machines, but maybe it was caused by something else.

EX: Nuclear reactor requiring 1000 concrete will produce 200 concrete (the default stack size) when recycled. It is a massive loss of ingredients, which is why the safety is on by default, but the loss can be minimized when combined with mods that change stack limits (or ignored if you simply send random crap items to be recycled).