Try and cram 800 objects (actually, almost 900, since most vanilla bigobs are in use as well) in 999 slots while retaining any space whatsoever for doing it orderly.
Why orderly? Just take next free number, ordering is done via listOrder (where applicable), not via IDs.
Probably already broken by the extra 150 corpse items added by Ivan's mod;
Ivan's mod will not interfere with your numbering in any way (unless he uses negative numbers, which is probably not even possible). It's actually you, who can interfere with Ivan's numbering. Always the mod with lower index can interfere with mod with higher index (if 0..999 rule is broken).
As for the handobs, the limit is actually 125, (since each is occupying 8 spaces), so my 200 already is well over that.
Yes, you're right. I missed that.
Having said that, I'm interested in your explanations.
Yeah, it will take a while. I need to double check everything, so that I don't say something which is not 100% true.
But in general, ideas are:
1. use all numbers, don't skip numbers just for convenience.
2. split your mod into more parts (master + 1-2 small additions; ideally master being the "real master", not "fake master")
3. I can increase the 1000 offset to something slightly bigger (e.g. 2000)...
4. ...or maybe, I can increase the 1000 offset for real master game only (to 10'000 for example) and keep 1'000 for mods -- would have some limitations, but who would make a total conversion for a total conversion?
-- that would require that you make your mod a real master, not a fake master
5. a combination of any or all of above
More details later.
PS. Also while your solution is true for normal mods, "master mods" are more severely constrained. Several solutions were proposed when the system was being implemented, but Warboy's defence of 'one 1000-size fits all' was absolute.
I don't see a difference in code between the "fake master mods" (e.g. PirateZ) and normal mods (e.g. Ivan's mod). Both use the 1'000 offset.
As written above, I could increase the range for "real master game", but you would have to stop referencing xcom1 and take it into your game directly.
Frankly, I don't know who even came up with the "fake master mods" idea, that makes no sense to me. It combines just the disadvantages of real masters and real mods, there's no advantage to it really.