I have great respect for Bacchus's canvas expertise!
I have done my own canvas work since I first purchased my Silverton 40' aftcabin back in 2005. Personally, I prefer the older methods for replacing vinyl. I shudder over the possibilities of the canvas shifting when sewing the vinyl if the old is removed first. Don't put too much hope in two sided sticky tape holding everything in place.
My sewing machine squats in my small one time bedroom crowded office along with my desk, table for printer, filing cabinet, credenza and shredder. I have no space for an extension on my sewing table to minimize sewing errors. Now Wifey.... that is a different story! She enjoy a HUGE bedroom for her exercise equipment and no way will she help to lessen my space problem.
I do though have my own suggestion for those intending to do their own vinyl installation/replacement. And that is to cover the sewing table not exposed to the machine proper with a good towel. Before I covered mine, I found my vinyl developed scratches from machine's table corners. But to each his own. AND I DO encourage folks to do their own canvas. It far from rocket science!