After upgrading from an older DisplayFusion version (9.x or 10.x not really sure) to 12.1.1, scripted-function hotkeys have approximately a 2-second delay on the first activation. Subsequent usages are immediately.

The delay doesn't happen every single time, but is particularly noticeable after DisplayFusion has been idle/restarted.

The script is a simple application mute while focused function (even from the script section on this website):
BFS.Application.GetAppIDByWindow() followed by BFS.Audio.GetApplicationMute() and BFS.Audio.SetApplicationMute().

I also tested disabling "New Assembly Resolver" in advanced settings, but this does not change the behavior.

Windows 10
Displayfusion 12.1.1