to be honest i'm not that experienced, i'm practically a lammer, i'm just very curious, and i'll go after my answer in brute force and alone. , the modification is the responsibility of LIBIL2CPP.SO, because it is in this file that contains the game code, the necessary dll and such ...
but as not everything is wonderful in the world, modifying il2cpp has been difficult lately, as devs are improving and protecting this file, but once you can break this protection, you can dump your offsets, modifying useful functions that will give you advantages in match.
what I'm talking about is obvious, but that's basically it, with the offsets in hand it's easy to modify in ARM, and create your own apk mod, either with menu mod, on / off button, it's up to you.
And it is worth mentioning that in the world of modifications it is not just about modifying il2cpp, there are other ways, using the game guardian is one (modification in real time without saving), luck patcher is another way, but it all comes down to finding correct offsets, addresses and etc ...
so, the programs that you cited are just to dump, just because in the dump file that you will find the offsets, then yes you can use in modification programs, DNSspy, Reflexil, IDA or whatever else there should be XD
and I wanted to have more time to dedicate myself to learn more about this world, but have a life out here, friends, girlfriend, parents and brother, here in my country it is common to be connected even as adults, with debts and problems to solve. ..
at the moment I take just a few minutes to read and try to learn something, and here on the forum I learn some things too, that's why I'm here every now and then!