Just to confirm, neither HDR@89Hz nor HDR@91Hz work, but HDR@90Hz and HDR@65Hz do?

Also, you can disable Unified Frame Limit Management to revert to the older split slider config to be able to set sub-61hz locks without removing changes entirely.

I will likely make an update which changes things such that even values between 91 and 121 get skipped over, in order to avoid trampling over 46-60hz options from unified limiter which already work.