It listed my LXR-02 (connected over usb/web midi) as "Supported" after I connected it, but it did not appear in the list of synths under "backup my synth", nor did "capture soundbank" do anything.
Speaking of the LXR-02, I just just finished this MIDI/patch editor: https://lxr02.greg.technology/ (free of course) - source code link in the footer
Here is what was happening: when the LXR-02 was auto-detected via Web MIDI, it wasn’t getting populated in the select dropdown, and the modal attempted an automated handshake instead of guiding you to initiate the dump from the LXR panel.
Speaking of the LXR-02, I just just finished this MIDI/patch editor: https://lxr02.greg.technology/ (free of course) - source code link in the footer