When you consider some of the god-tier champs who are able to abuse the map best, it is the speed shrines/mobility that are a huge influence on it. I'm doubtful if map design changes like this will be explored, though it would be interesting to see how Dominion would fare without it

So long as you can, with about average MS with tier 2 boots, go from speed shrine to speed shrine without the buff completely fading, I think that is fine. Maybe instead of the full decay that is on the TT shrine have a decay from 100% to 50%?

Don't put this on dominion nome!! Leave it on TT =(