When I worked for our college IT dept, we had a lot of theft of computers.
The Kensington lock hole is worthless. The thieves would simply yank or pry the cable right out of the hole. Sometimes they could even do it with minimal damage to the computer.
What worked is a sheet metal panel with double-sided tape and a steel cable with loop for locking it to the desks.
The panels can be bought in various sizes. Larger = more surface area = harder to tear off.
Now, these were not designed to be removed, ever, so this may not be a good choice for you. Double-sided tape can be removed, but it’s a pain. The way I do it is cut the foam backing in half with a razor, then remove the metal panel to expose the remaining tape. Some heat from a hair dryer makes it easier to peel the remaining tape off. Takes a while, but that’s why it works.
The other option is to lock it in a box or case that is itself hard to steal. It might even be possible to cut holes in the box/case for cables.
If it were me, I’d probably figure out a way to clamp it to a pedalboard or flip-open case.