I have tested it out so you guys so you don’t have to! They throttle your account when you buy a lot of boosts or mine a lot. I tested it out with 3 accounts. 1st account has 8x15 boostss on 2 devices. The account makes 10 satoshi per 1k hash. 2nd account has 4x15 boosts. It makes 20 satoshi per 1k hash. 3rd account has no boost, it makes 40 satoshi per 1k hash. They will keep cutting earnings of your account if you end up buying boosts or mining for a long period of time.