The Lantronix Spider and SpiderDuo both now support HTML5 for the viewer with the latest firmware. Virtual media is still Java only.
I think the first version of the HTML5-capable firmware was pulled and then later re-released because of problems, which is what that reddit thread talks about.
SpiderDuo is basically hardware v2.0. It has VGA/USB cables that can be replaced, so that gives it a slight edge. The VGA cable wears out eventually. I have several Spiders from probably close to 15 years ago that I had to throw away because the video cable and/or VGA connector wore out.
If any of you run into this kind of issue again (v1), I would be interested in attempting to rebuild the video cable for you (probably just a little soldering) (you pay shipping). (electronics hobbyist, and landfill critic).
PS. This offer is “as time and resources allow”