I don't think a 90 Super Tigre is too much for the 4*60. I would certainly use throttle management when necessary.

I have one with a Sport Jett .76 and Dub's tuned pipe, which should be comprable to a 90 (or so, LOL) and it flys great. Actually, it's a rocket, but that's what the left stick is for, yes?

There are guys that have 4-S 120's on them with no problem.

Good luck and have a ball!