Yes, back compatibility is needed. I've forgot tell you that some communities have own REAPER accessibility plug-ins. For example, russian community uses "Ear". It has developed by russian programmer therefore it is no popularity in european communities. This plug-in does many other hacks but does not touches the FX chain window. And some users already felt uncomforts.
I have quickly checked on my primary computer. EZ Drummer works for me, with old and new OSARA, with old and new NVDA. So if there are still some incompatibilities, I will need the information about precise versions of everything.
From what I remember, Ear is not free and not open source. The documentation is not perfect. I guess these factors play primary role in its limited popularity. In the time of global Internet, nationality and residence should not play any role. I know that unfortunately some people think differently. But in reality there are no computers completely made in Europe or US and there is almost no software which was developed without someone who is or was born outside of Europe and US. For example SIBIAC is "made in Germany", originally for one single US user, written by Russian programmer attracted to such activity by a person from Turkey.
