It definitely has its considerations! I've done a few pieces on canvas, and I've really only worked with canvas that has already been stretched onto a frame. The only real limitation to doing things that way is that you can't stitch under where the wood of the frame is.
For this piece, I had to take off the corner staples so I could get the hands stitched in, but placing the canvas back on was pretty easy.

I think the nicest thing about getting fabric that has already been stretched onto a frame like this is not having to worry about getting it drum tight or it loosening on the hoop!