The hxcpp garbage collector is not a very poor garbage collector, particularly when you enable the generational gc mode and data exchange is much more efficient than it normally is in those situations - pointers to Haxe-internal things can be directly pinned and accessed and the other way round it’s even easier (see for example Kha’s array buffer classes). The hl/c garbage collector currently is indeed pretty slow though, also C/Haxe data exchange is still limited compared to hxcpp.