IIRC the feature frequency is 1/275 on it, so you're pretty much bang on the money there. If not, it was 1/250 but something in the back of my mind says the former is right.
Yeah 10K spins is usually enough to make a decent stab at average feature frequency, you'll generally be within +/- 10% in either direction at that point in my experience.
As for MM2, not a bad game IMO, as long as you know what you're getting yourself into.
One thing I would draw attention to is my RTP, which at 94.64% over 11,562 spins is below T-RTP on this game, and represents a loss, but would be
above T-RTP on a 94% slot!
With a 96.xx slot I can be below the curve and take a modest loss over that spin number, but it's not a wipe out. Do that many spins on a 94.xx slot and run a couple of percent below T-RTP, all of a sudden you've been getting 92% which is going to brutalise a balance. Also you're going to, on average, get far more spins with a 96% slot, which gives you a greater 'hit zone' in terms of getting those decent wins and features, whereas on a 94% slot, you'd be long bust out.
I know I've banged this drum enough in the past already, as have you dunover, but it can't be stated often and loudly enough how insane 94% slots are from a player perspective. Steer clear!
There is no way on earth I'd try this sort of shit with a 94% incarnation of MM2.