UCP call forwarding buggy when forwarding to extension 0

I'm trying to forward calls from a phone extension to the number "0" (which is a misc application or a custom extension) using the PBX.

Forwarding to 0 works fine when set on the phone by dialing *96{extension}0. BLF hint gets updated and the forwarding works, yet this forwarding state is not reflected at the call forwarding slider in the UCP control panel.

If instead of doing this on the phone, I toggle the slider in UCP to enable forwarding and enter 0 as destination, it has completely weird behavior: The button toggles to Enabled, only to revert to Disabled after a second. Watching the BLF hint I would assume the forwarding gets enabled properly, but due to a bug this never gets reflected in the UCP slider state for more than a second.

I initially thought this is because somehow "0" is not properly recognized as an extension, but I can properly forward to extensions like "1" or "2" which actually really do not exist on my FreePBX installation. So my guess is, this is another php (isempty) problem like in FREEPBX-22729, which detects the string "0" as empty/null and then UCP assumes no forwarding is set, even though forwarding is set to "0".