Thanks for the reply, I checked my registry and extracted the data
I attached my DISPLAY.reg here:
https://pastebin.com/e6hwf7K6
My displays share a very similar base instance path, differing only by the UID at the very end.
Main Monitor (PL3466WQ): IVM761A\5&2cd6120d&1&UID37121
Side Monitor (ANMITE): RTK1920\5&2cd6120d&1&UID37124
TV (Beyond TV): TCL9653\5&2cd6120d&1&UID37120 (this one is disabled for now)
There are other unique identifiers inside these registry keys that you might be able to use to disambiguate:
Address: They have unique hex addresses (00000111, 00000114, and 00000110 respectively).
ContainerID: Each display has a completely unique GUID assigned to it.
2. EDID Uniqueness
Yes, the EDID hex blocks inside the Device Parameters are 100% unique for each individual display. They do not overlap at all:
IVM761A EDID starts with: 00,ff,ff,ff,ff,ff,ff,00,26,cd,1a,76...
RTK1920 EDID starts with: 00,ff,ff,ff,ff,ff,ff,00,4a,8b,20,19...
TCL9653 EDID starts with: 00,ff,ff,ff,ff,ff,ff,00,50,6c,53,96...
Hopefully, this helps you adjust the display identification logic! Let me know if you need me to test a beta build.
PS. I noticed one more detail. My main monitor (IVM761A) actually has two different subkeys in the registry: 1&8713bca&0&UID0 and 5&2cd6120d&1&UID37121. One of them is an active profile, and the other is an inactive "ghost" entry (likely created when I changed a cable or GPU port in the past).