-Items thrown by thrower stack inserters are not actually stacked when they land
-Thrower inserters of all varieties do not throw at underground belts or splitters (is this to do with item overflow calcs not working on these?)

Overflow prevention is tricky with splitters so I only did regular belts way back, but now that I'm older and wiser I could probably implement it to work on underground belts. Splitters are more complicated, I think I'll just have them not throw at splitters if overflow prevention is on.

As far as I know there's no way to add items to a stack with the API, but I could create stacked items when they land on a belt I think, I'll have to check it out

Thanks for the response. Hoping something comes of thrower inserters working with underground belts since that'd help me integrate more throwers into my spaghetti, lolol

One other thing, would it be possible to add some type of tick box for override protection for individual thrower inserters? Currently I'm running into some annoyances with thrower inserters getting stuck with spoilage in their hands and not being able to throw. I'd be fine with just hucking the item at the building and having it bounce off and land on the ground, I can just use recursive blueprints to run an occasional cleanup routine, but the inserter being totally stuck with spoilage in hand isn't ideal.

Sure the tick box seems easy enough, I guess it would only matter when overflow prevention is turn off but I think it makes more sense than the other way around