David Weaver
yes on both - beyond the level of trouble I'm willing to go for. The spray appears just to be more or less a finish with PTFE in it (no oil, though there are bunches of products with PTFE added to water displacers or thin oil).

The spray should last long enough to experiment, but I'm not hoping to have teflon on a cap iron in the long term - just test an idea, so if it's gone in 20 strokes, that's OK.

A strong application of carnauba is also a good idea.

Hard to tell the difference in bending or friction forces at different angles (because there's more bending).

I tried a flat 80 degree bevel like shown in the K&K machine video. It's not very pleasant. It's either not preventing tearout, or it's like pushing concrete blocks filled with lead.