I can tell you this, if the T1 get's built and runs, I could give a flip less what tender is attached to it. It would be optimal for it to be near exact to the original, but to me not a show stopper by any means.
These guys keep on surprising me, pleasantly so, and I will keep watching. I love the T1, my second favorite streamliner. Since my first favorite already runs being a daylight GS4, this would be some real icing on the cake.
This group seems well qualified and is constantly making progress, so I am enjoying the run so far.