Interesting questions! Got me wondering myself about this as I’ve just been ignoring that yellow render bar these last few months since starting working in premiere.
I’m working on a project now where all the footage I’ve been handed has been transcoded to prores and everything has a yellow render bar over it.
But just did a test: took a prores file that was giving me a yellow render bar, transcoded it to a dnxhd mxf in media encoder, imported that to premiere, created a sequence from it, and no yellow render bar on that sucker.
Gonna do a bit more research and try to run a more extensive test in the next couple weeks, see if there’s any noticeable performance improvements. Will let you know if I find anything else out.