Does that mean I can also use those in auto exec scenarios?

Yes

@hius07
Do you need to create a Dispatcher item for this? (For profiles and gestures)

I just had a quick look at the files changed, and dispatcher.lua is not one of them

That's how the Book shortcuts plugin works: adding a shortcut means adding an action to Dispatcher.

I think I found a bug when testing this: #7917 (comment)

I created Book shortcut pointing to the script.
This script is being used as action in a Profile, that trigger on book opening
I then remove the script from action and switch back and forth books - the script comes back again. It is again checked in the profile.
Weird!

I then had to remove the book shortcut to prevent this behavior

You are overwriting internal settings files while the program is running, not good.

I was only touching gestures.lua, not profiles.lua though...

Can you recheck? All actions are added/deleted to profiles in the same way.

I'll double check soon.

My bet is KOReader tripped after I killed it :D

On crash (or killing) the settings are not saved.

Yeah, I remember this.

But the profile mishaps happened after I restarted

@hius07
I double checked with an empty script file.
All good.

#13393 (comment)
The previous wrong behavior was probably related to re-writing files on the fly.