Sure, my solution works well and it’s just one line of code, but it’s quite an ugly hack.
Do I understand right that we only have access to the compiled mod-ui/utils? Midi Channel Filter - #6 by Giedrius. If not, I would recommend to fix it directly in utils_lilv.cpp.
It seems that meanwhile moddevices corrected it: mod-ui/utils_lilv.cpp at master · moddevices/mod-ui · GitHub