I completely undertand your reluctance.
Maybe only make it available after you've beaten round 50+ for the first time, since first time players probably benefit from watching the battles strategically.
Just to be clear, i would prefer not skipping the fight, but just speeding it up.
Maybe make a 1.2x multiplier available when you beat lvl 20, a 1.3x when you beat 30 and so on.
Anyway, whatever you do i'll still, be playing the game lolol cheers