Two questions; 1. can the wheel truing jig, TT-50, be used on a high speed dry grinder (with the proper anchoring) without ruining the cutter tip? 2. I recently purchased the T-7, and right out of the box I was pleased with sharpening my user chisels, until I came to the 1/4" ones. For some reason, they did not sharpen square. I am a little reluctant to move on to my Stanley 750's and witherby's. I probably am a novice of the novices, but evidently I am doing something wrong. Maybe someone has a book "Sharpening for Dummies."
I would not use the TT-50 on a dry grinder, under any circumstances.
My guess on your narrow chisel is that it squirmed away from the reference shoulder as you tightened the clamp. That happens a lot with narrow tools.
You can try mounting the small chisels in the middle of the jig (I do that with anything as the shoulder of mine is not square and on the side it is hard to set the clamping screws to exert the same amount of pressure) and tighten the clamps the same amount in small increments. You should use a small square to check for square along the side of the chisel. As you grind check for square again, this time the cutting edge and adjust as necessary using the method described at this link:
http://www.sharptoolsusa.com/squareedgeweb.pdf
I was able to successfully sharpen 1/8th Japanese chisels and rarely had to adjust something during sharpening after I first time set the tool in the jig.