Ads are distributed in 3 different groups:
Which means that even if players decide to watch all the ads from a group, they’ll still be nagged by ads from another group and the worst part is finishing a run and being nagged by an involuntary ad that freezes the game until it starts, while that ad could have been watched later for 5 gems.
Sure, this distribution puts some ads aside that could be used to revive but the majority of the players will probably use the rest of the ads for Bonus Offers before they get a chance to revive.
I understand that you want to guarantee that there are always ads available in every group but you should also consider a plan that benefits invested players that are willing to watch all the ads and want to maximize the rewards. If a player wants to watch all the ads for gems, he should be able to watch ads from all groups until there are no more ads available.