Compounding the dosages of same-size 10 and 20 that way would 'hide' who gets what, but that can be achieved simply with same-size 30 and 50mg pills. (As for titrating up the placebo arm, a stock of 10mg pills takes care of that.)
I've never seen the dosing disclosure in a trial so "restricted to maintain blinding" (citing the corporate presentations). I wonder if Doc328 has any insight here. Every blinded trial I'm familiar with, the dosages were publicly disclosed. This is what is different.
Anyway, we'll find out more around July.