Wikinaccurate claims they have a bunch of Embraer ERJ-145s, some of which were originally intended for the Glasgow–Stornoway route. I suspect the Plague may have put their introduction on hold.
It was certainly one of those.
Jets don't seem suitable for this route, to my understanding, turboprops are more efficient at the low altitude + take off landing phase.
The routes out of Stornoway basically take off, climb to altitude, cruise for 10 min, then start descending.
They could have been tailor-made for electric flights.