I had the fixed scheduler in a context object; the code base was ported from r4j  to RxJava some months ago when I didn't know about the plugins or the customization options. I knew the removal of ```executor()``` will affect me soon and set out to either wait for a fix/alternative or create one myself. 

"When in doubt, leave it out." If this part of the proposal creates doubt, it is better to leave it out for now. I have a bunch of leftovers from other PRs so I'll just have them in my repository / personal library.