I also clearly notice the "blanket effect" on modular systems.
However, compared to the M4 (I had one), in the new Syn2, this effect is felt much less. All my modules sound much lively and brighter on the new Syn2 than on the old M4. I think that the main problem lies precisely in the preamp, and not in RT2 / 50. Many switching switches, somehow worsen (detach) the sound. In addition, an additional tube at the M4 output (in my opinion) also strongly influences the character of the sound of the M4. In the Synergy line, many of these problems are resolved, and in the end I sold M4 and bought Syn2.
Now I use it with my RT2 / 50 (MDA mod) and very satisfied!
Yes ... I only use Salvation Audio modules, they are the best for me))).
I hope that helps
Max