Apologies for the necro. But I just got a Aimos 4 port Synchronous KM switch and tested some devices that I have

Keyboard:
Steelseties Apex Pro TKL - Bad. Shuts off by itself 5sec afterplugging in. Idk if it's power hungry enough that its shutting itself off
Corsair K63 Wireless (Test both wired and wireless) - Bad. Keymap not properly mapped., some keys are empty so not fixable by powertoys
XPG SUMMONER - Bad. Same with corsair, Keymap different from what I'm pressing. Some keys are empty
Azio KB505U - Good. The only keyboard that I own that works.

Mouse:
Razer Viper Ultimate V1 - Good. Works, macros stored also works.
Razer Pro Click - Good. Works, macros stored also works.
Razer DeathAdder V2 Pro Wireless - Bad. Doesn't work. no movement or clicks registered