I think it's really personal preference maybe balanced against how much effort to remove stuff. When we had sheet vinyl installed, I removed anything I could so as the new flooring was as factory as possible.
If interested search my user name for pictures and details of what we did. Best change ever we did to the coach.
Vince and Susan
2011 Tiffin Phaeton 40QTH (Cummins ISC/Freightliner)
Flat towing a modified 2005 Jeep (Rubicon Wrangler)
Previously a 2002 Fleetwood Pace Arrow 37A and a 1995 Safari Trek 2830.