I have experienced similar issues with scaling, losing countless days trying to figure out the issue... going as far to even question if GSAP is the problem. Your observation was a HUGE clue into what the problem was.   Scale values change at an even rate, but what those values affect don't. As scale increases, the rate of change decreases, causing an animation to slow down. Linearly, there's a difference of 500 between these two changes, but their scale factors are completely differen