Dumb trainer power by weight

Hey! Hello people!
Im started riding(38years ago) before i learned how to walk. I was 130 kg and i went down to 89 now im 118 So i know if you are heavy-er you need deal with bigger resistance…
I have a TACX Blue Motion Trainer, and the level 4 is very easy… Compared to if i take my bike and just ride on flat i need lot more power then on this level 4 trainer… Couse my weight.
So please make some settings in zwift where you need to change the resistance if your wieght is under 90 you need to use 4 and 5 if you 100+ Or Just give an option to change to level 5 and teach zwift how many watts is that… or something please!!!