Maybe forgot to call .flush() on FlxSave

@ashes999 After looking at the flixel code, I admit I was mistaken. The reset() function isn't called, but revive() is, so you should override it and put your stuff there. Sorry for confusing the functions! I will edit my reply above!

In the original question you were doubting whether you should "remove entities that are off-screen". Yes, you should remove them from FlxGroup and also destroy them (Non-Recycle Way)

try lime rebuild windows -Dlegacy

Good luck!

There is not only cost of creating new sprites, but also cost of storing them in memory. If you create 1000 sprites, you have 1000 sprites in memory. If you recycle 1000 sprites with 2 sprites at screen max, you have 2 sprites in memory.

I believe the best way here is marking them exists=false when off-screen and using recycle(YourType) of FlxTypedGroup<YourType> to create new sprites. Just don't forget to reset all variables of sprites to default values after recycling them (only revive() is called automatically).

(I edited the answer, turns out the reset() isn't called on a recycled sprite)

Apparently, you have to provide all the tiles to loadMapFrom*(). If you are generating the map procedurally, you can set the array elements first (not zeros, but real tile values) and then pass your array to loadMapFromArray(). If you are making drawable or destroyable world, then I believe you have no other choice.