Single point, zone, or wide? (auto focus)

Some information rather than advice. The following is primarily based on personal experimentation, and it could be wrong in spots. It's also based on an X-T10 with firmware 1.20, and may not 100% apply to other configurations..

1. Most AF situations seem to use contrast detect rather than phase detect. Contrast detect can be recognized by a brief lens "pump" when focusing in AF-S mode, and continuous lens pumping in AF-C mode. I believe that when using contrast detect, you should set Release/Focus Priority to Focus, lest the camera snap a picture while pumping.
2. Point focus -- when the selected point is one of the nine phase detect points (large crosses) -- seems to use phase detect except that sometimes it follows up with a tweaking via contrast detect (as evidenced by very brief lens pumping). Obviously, if the selected point isn't one of the phase detect points, you'll get contrast detect.
3. Zone focus is the only AF mode that I can find that reliably uses phase detect. However, if the actual zone size and position results in it including any contrast-detect points (the small squares), contrast detect is used.
4. Wide/Tracking mode nearly always uses contrast-detect mode. Fujifilm says so for Wide (AF-S), and experimentation suggests it's also true for Tracking (AF-C). The one exception is with AF-C and CH continuous shutter (see next item).
5. Either Zone or Wide/Tracking with AF-C and CH continuous shutter uses phase detect, except that sometimes the initial focus can be followed by a tweaking via contrast detect. Unsurprisingly, in this configuration, the AF zone is restricted to the phase detect AF field. Zone mode lets you select and position a 3x3 box within the phase detect if you prefer, while Wide/Tracking forces a 3x5 box covering the entire phase detect field.
6. Face Detect always operates in Wide/Tracking mode and therefore always uses contrast detect.

So, back to point #1: unless you have a reason for needing Release mode, I suggest keeping Release/Focus Priority set to Focus for both AF/S and AF/C. Oddly, the factory default for both of those is Release.