If a user has "Do not process muted tracks" disabled (Preferences/Audio), it still should be/get enabled automatically during rendering so save time.
DONE (5.20pre5)
This also should apply to the "Apply FX" and "Glue" render functions where the user can't do any work in the arrange.
Tracker:
http://forum.cockos.com/project.php?issueid=2340