Michael Beijer 

I don't think there are custom shortcuts for this.  Only Ctrl+Shift+Enter to insert the selected translation.  I guess an AHK script could solve it to suit the way you use this feature... and maybe worth suggesting the additional built-in shortcuts in the ideas site.

Thanks Paul! I'll post it as an idea if I have a moment.

I've created a quick workaround, where pressing:

Alt+x
Alt+c
Alt+v

… one after the other, automatically inserts the (1st) translation present in the AI Assistant pane.

To make this work, I set the following two shortcuts in Studio:

• AI Assistant: Alt+X
• Apply Selected AI Translation: Alt+V (Editor > AI Assistant)

I also run the following small AHK (v1) script:

!c::
Send, {Down 4}
Send, {Space}
Return

The above script is triggered after the AI Assistant window gets the focus, and clicks Down 4 times, and presses a space, which selects the translation.

I'm sure I can figure out a way to reduce the number of shortcuts, from 3 to 1, but this one works for now so I will use it until I have more time.