Dont ever use a screwdriver, try a popsicle stik or similar or plastic fork handle end.
Problem with hoseclamps, they are not perfectly round, they have holes that may allow something to hang up..the shim of softer material wrapped inside the hose clamp is rounder, softer, and less damaging.
Regarding the bevel or chamfer, any is better than none. I realize the sleeve is thin there on big bores, but it is not load-bearing in use.. just be careful when moving cylinder while off the bike..cand chip or deform easily.
Hastings makes some beauty compressers that are like shimstock, with a clamp that curls it tight, and a quick-relest, they have worked well for me on other sizes..