I have seen the twist mount + TMIC combo used a few times in the US forums. I can't imagine the heat soak is any worse then the stock location. Just remember that all our clutch and brake reservoirs are going to get in the way and get even closer to the heat of the exhaust housing.
I am in the same situation as you, I want to keep my TMIC, so if I do upgrade the set-up I really want another stock location turbo. I really like the EFR kit; keep stock location, able to retain TMIC and EFR turbos spool incredibly quick. The only downside is the cost, but for me the final product seems to justify the cost.
