Hello, tell me please. When using Vukoder Premiere option "Use Maximum Render Quality" affects the quality? Do I need to use it?
No, you can ignore it.
Adobe claims that it affects scaling quality, so if your edits have been scaled in premiere (this may include time remapping), it may improve the quality. If you haven't done anything like that, it probably does nothing.
It's likely something that's applied before Voukoder gets the video data from Premiere.