This is one of those times you're over-thinking a non existent problem. If you have a box full of reels, then use the ones that have no fastener of any kind. Every reel I've ever used that had a fastener was the reel that was a btch to thread, and the most likely to buckle the film and cause totally undeveloped and unfixed areas that ruined the roll.
Agree. I always had trouble with hooks and clips - seemed the film was always off-center so it buckled. I have a couple of reels with clips, but just stick the end of the film into the center of the reel and wind it on. No problems.
Moma don't take my Kodachrome away!
Oops, Kodak just did!