I thought of that, but it doesn't at all feel like a "hard" misfire one would usually get from a spark problem. It's more of a soft one one gets from a weak fuel supply if that makes sense.

Not saying it can't be electrical, of course. The plugs looked very good when removed for the compression check. The wires look new. Obviously it wouldn't hurt to check.

Sometimes cranking 15 sec vs immediate start could be a bad leak of the coil output to ground intermittently I guess.