Just my 2 cents, looking at your picture, it seems you already have supports at the bellhousing and maybe one at the front of the engine.
You got to have some movement for torque. Seems adding a support at the tranny could cause it to take the load and crack the case.
Probably better without one.
Note the 2-point comment in the above post.
The vehicle that tranny was in, probably only had one support on each side of the engine, therefore the tranny mount created the 2-point system.
I think you and John are correct. I fabbed that member last night before I read anything here and just to see how it fit.
But the T5 mount is rubber w/ 2 contact points on the T5 and then just one to the x-member. I certainly seems designed to allow for some play and movement.