Does turning on Google Drive note upload re-upload my note every time I edit it on the device?

No. A note's Drive copy is written only when a task linking it is pushed (or re-pushed) — there's deliberately no background "re-upload on every device edit". Once a note is attached, editing it on the device afterwards does not touch Drive until another task linking the same note is pushed. The upload only happens at all if you've connected Google and explicitly enabled note upload.