By the way, maybe I didn't read carefully, and someone might have already suggested it, but you could significantly reduce the impact of the Grail by simply prohibiting the use of the bug where a hero digs every day using manipulations with movement points. This was actually specified in some recent tournament.

If so many people don't like the Grail, it seems that, on the one hand, it should be reduced. And on the other hand, nothing is artificially banned; the existing bug-feature is simply fixed.