Joe Roxx

DaVinci Resolve has quite a bit of a learning curve (for me at least). I use it mainly for stabilizing videos.
Try VSDC or HitFilms. Like DaVinci Resolve, the free versions have enough features available for most needs. VSDC is more fully featured. There's a small cost to upgrade to a "pro" version which enables hardware acceleration especially handy if you have video card that you can utilize for video-related tasks.
 

@jkmccarthy @0301chris
X-T200 - Since there isn't any controls to the camera settings in Webcam mode, I do not use the X-T200 as a webcam. I have continued to use my Sony a6400 for this purpose instead. I do think you're on the right track - if there's nothing that can be done via software or in-camera in Webcam mode, then the next best thing is to change the shooting conditions in your environment - in this case making lighting adjustments.
The XC15-45 lens does have some surprises. With better lighting, it does seem to "focus hunt" less. In some cases, even better than the XF18-55. Also, the XC15-45 "remembers" the last focal range you used. So if I set it to 30mm and turn it off and the lens retracts, when I turn it back on, it zooms back to 30mm. I do not recall any other zoom lens that does this. At least not the ones I've used.
If you're using Zoom, there's a video setting in the Zoom client that will allow you to adjust for poor lighting conditions. This may help to brighten your appearance in the video conference to some degree.
X-S10 - Still no luck with the X-S10 as a webcam even with the most recent firmware upgrade. The only "progress" is from the post by @davidkrol. I think that footnote is recent as I don't recall seeing that previously. It does help make the X-S10 somewhat usable as a webcam but that defeats the purpose of the X Webcam. In a way, it puts in in a similar boat as the X-T200. 
Clearly, the advantage here is on the Sony a series + Imaging Edge.
I've still kept the Fuji cameras. But recently, Tamron has released the 17-70mm lens with VC (their version of OIS) and it appears that the stabilization is amazing. I may consider parting with some Fuji gear.
@0301chris For a mirrorless webcam - did you look into the Sony option further?
Good luck to all.

Thanks to @Joe Roxx, @0301chris, and @flamidey for the guidance on capture cards. And fingers crossed that the X-S10 gets full Xwebcam2 support, but given that we don't know when or if that will happen and what the resulting quality will be...I decided to experiment on the cheap ($26 total) with: 
Micro HDMI to HDMI Adapter Cable, Wenter 6.5ft/2M Micro HDMI to HDMI Cable (Male to Male) for Gopro Hero and Other Action Camera/Cam with 4K/3D Supported Video Capture Card, GUERMOK USB 3.0 HD Audio Capture Card, 4K 1080P60 Capture Devices for Gaming Live Streaming Video Recorder, Compatible with Windows Mac OS System YouTube for PS4, Switch, Xbox So far so good. It's the same level of control (everything set up on the camera), but with a much better image (full frame rate). Wishing I had pulled the trigger on this from day one.

I think Face and Eye Detection will need to be disabled for the autofocus range limiter to be available.

DaVinci Resolve has quite a bit of a learning curve (for me at least). I use it mainly for stabilizing videos.
Try VSDC or HitFilms. Like DaVinci Resolve, the free versions have enough features available for most needs. VSDC is more fully featured. There's a small cost to upgrade to a "pro" version which enables hardware acceleration especially handy if you have video card that you can utilize for video-related tasks.