I'm pretty sure Thoughtseize is just better right now, as you really want to nab swords against maverick in order to race them, it resolves more often against rug, and it is better with Temporal mastery as it costs less and can be played usually the turn you mastery if you have to do it early.

I'm also trying an Island instead of the 9th fetch (obv playing 4 misty/4 delta now) in order to more effectively set up mastery through wastelands. Seems fine so far, haven't really had much trouble with the manabase with the 1 basic. Also nice to give path a drawback.