Waiting for the survey, but one funny thing I noticed. The OGL 1.2 says it uses the 5.1 SRD, and the 5.1 SRD says it is ONLY usable through the OGL 1.0a ...
Of course not! 1.2 isn't released yet. It is a draft for commentary. When they do release, expect a re-release of the 5.1 SRD with appropriate license.