Gate with its normal XP cost is still Gate. As long as the DM only nerfs it into the Bronze age, rather than Stone as I probably would, it should still give the game a good bending at the very least. And if you suffered through 18 levels of misery (1st doesn't count since TNs are almost good by the standards of that level, prior to their TS DCs beginning to skyrocket) to get to Truenamer 20, you deserve something for your trouble.