To update, since I first started this thread, the first opening time has gone from 13 seconds to 15-20 seconds to 25-30 seconds and, this morning, 35.7 seconds (subsequent starts are ~1 sec or less). During this time, I've gone from a Gigabyte Z68X/i7-2660K setup to a Z97/i5-4690K, and just this week from a fast 128 gb Plextor SSD to an even faster 256 gb Samsung 850 Pro, accelerated with its Magician software. Strange, puzzling situation.
For a good year before this started with xyplorer, I had one program that was even worse: Vuze (Azureus). When I opened it directly the first time in a session - vs. from a torrent link which opened at ~normal speed - it would take close to a minute to start. Its GUI would show most of that being at the beginning while working its way through a ton of plugins. Like with xyplorer, the developers didn't have any explanation for this behavior. Now with the new setup, Vuze starts instantly, but xyplorer seems to be going in the opposite direction. The Vuze experience does make me wonder if there isn't something similar going on here, that is, how xyplorer handles the loading of plugins, or whatever it does early on, that is slowing its enormously.