I imagine that you will be satisfied with the updated xhc-whb04b-6 component by hdiethelm, which allows the pendant to reconnect in case it disconnects (as well as several other improvements). But you need to compile it from source, same as building LinuxCNC from source (which is not all that difficult). He made a backport to LinuxCNC 2.9.8:
github.com/hdiethelm/linuxcnc-fork/tree/...x-v2_backport-v2.9.8
So basically git clone that repository, checkout xhc-whb04b-6-fix-v2_backport-v2.9.8 and then compile. I don't know about exact version compatibility, but I don't think you actually need to use v2.9.8 to run the component. You can just give the full path to the newly built compnonent binary in the loadrt command.
I made a custom firmware for the USB dongle that I use myself, but I can't really recommend that for others. There is a decent risk that it would irreversibly break your dongle in case the hardware is slightly different than what I have.
I don't know your proficiency with git and compiling LinuxCNC from source. Just ask if my somewhat terse instructions are not clear to you.
