It used to work on x2 multiplier, but they catch you nowadays. Should work on all single player stuff like 9-10. You still need to level your team to around 100 though with ok-ish gear even with hacks on so the stats/dmg gets multiplied. Don't use on any multiplayer or ranked things.
Only if your CPU/emulator is x64 based, and signature verif is modded like using corepatch or luckypatcher, so kinda requires root also with root hiding. So far the only thing I have seen that works on android 9+ is magisk delta debug with lsposed+corepatch as luckypatcher either doesn't like doing x64 based systems or higher android versions, or both. ymmv.
It has never worked like that, even 2 years ago. It's impossible and has 100% been detected without fail. It did at one point work with 2x multiplier on the regular dragon raids but never again. Maybe a 1.2x multiplier might work since they're probably used to seeing 2x or higher, but still heavily unlikely. F2P gets hit really hard once you reach that near endgame.