I’ve had a look through the action directory and by long-pressing ⌘, but I can’t seem to find a way to invoke a search through all actions using a keyboard shortcut. Anyone know if this is possible? Apologies if I’ve missed anything obvious. Cheers.
Same question here - External Keyboard Shortcut for Searching Actions
No answers though 
Sorry. Missed that one! I also find it awkward that you can’t simply ‘escape out,’ of the action search box when it’s populated; you have to physically tap on the cross in circle on screen. Hopefully this will be addressed to at some point too as it feels like a conspicuous anomaly considering the otherwise excellent support for keyboard shortcuts throughout Drafts.