> How unique are these ids really? I imagine certain apps will be very commonly installed as well as certain groups of apps?
Probably worse than you think. Zoom, Skype and Slack will be very common on work computers, while game launchers like steam and epic will work quite well on gaming pcs. You can differentiate further by checking the mixing of those groups and their relative music client (Spotify, ITunes...). Of course it won't be full 32 bits, but given the amount of quite common programs with url handler, it will probably deliver quite good results.
Probably worse than you think. Zoom, Skype and Slack will be very common on work computers, while game launchers like steam and epic will work quite well on gaming pcs. You can differentiate further by checking the mixing of those groups and their relative music client (Spotify, ITunes...). Of course it won't be full 32 bits, but given the amount of quite common programs with url handler, it will probably deliver quite good results.