/diy/ - Do It Yourself

figure this is a good thread to post in.
I have a nasty looking old brown toilet. It's completely sound, so not replacing it, but the wax ring had rotted away and had been leaking on my carpet the level below (just purchased the house btw).
The old PVC flange was cracking and falling apart, so I cut the PVC just below the flange, installed a new stainless flange, and reseat the toilet with a fernco waxless rubber seal.
My question is, should I support the PVC elbow more where it comes through the floor below, or is it fine just 'floating' from the nearest strap (about two feet away) to the fernco flange.