I always use raw chemical for preparations of solutions.
Reversible process b & w you should read densities of film.
At least fog density and high density.
From memory, the Kodak Double X (as reversal process b & w) fog was ~ 0.3 and maximum density was ~ 2.6.
If you look at the characteristic curve of KODAK TRI-X 7266 is not
as rich in density curve as a negative film.
Again, I think better results can be obtained on films with small fog.
I have not worked with KODAK TRI-X.
Do you mean that KODAK TRI-X 7266 is lower contrast than a Tri-X negative film? That doesn't make Super 8 Tri-X sound too good from my experiences with Tri-X 35mm.