Hm.
Well, I'd like to try to keep things nice in here. I think a difference in play styles is the root of this - often MP vs. SP or PBEM issues are seen very differently. Also, some people play to WIN and some people play to look around and breathe in the feeling of the map.
I agree with Air Warlord's assessment, and I am primarily a MP WIN-first guy, but I can enjoy lazy exploring and I don't really side with his tone - my way is my way, but not necessarily the right way. I've never had the computer throw a mastery on me in a RMG - and if it seems that I could take it down in a few turns without much effort, but I could be wrong here. Now, on other maps (Elqueens big map, I forget the name) of course it's there - it's an important part of the map. I've very much enjoyed the challenge of teams games where my enemy threw up a mastery spell and I had to rush/sneak attack to bring it down quickly before I lost the game. Those have been some very very fun games.
For most SP players, do you normally play custom maps or RMG? If custom, like air says it can be turned off. If RMG, I don't have a good solution I suppose. Making the research cost be more (not casting or upkeep) would I think make it harder for the cpu to cast it early, and would not make it any harder to disjunct it.
If it's really a big issue, I'm sure stranger can make two versions of the mod, one with and one without - it would sort of be a shame because to play against each other people must all have the same version and that will reduce compatability. But... arguing back and forth is a shame too.
Instead we should celebrate how geeked we are about this new beta and all start screaming at stranger to get it done quicker, quicker!!