I would keep the stock wastegate even with the tune, I have read quite a few accounts of people having to go back to the stock wastegate with a Hilton tune because they were having issues.
The wastegate upgrade is mainly designed for bigger turbos.
MTE would probably be fine but I'd be very surprised if you got the same power levels as Hilton, and he doesn't offer any dyno results whereas we do have results for Hilton.