Maybe something like: https://www.homedepot.com/p/Everbilt-1-1-4-in-x-5-ft-18-Gauge-Thick-Zinc-Plated-Slotted-Steel-Angle-15152/332733420
Not aluminum, but galvanized steel, so should be ok in moderately wet environment. Plus, it’s cheaper than the 1/8” aluminum angle at HD. You could prob get 2 strips from each, or they may even have longer lengths for cheaper.
You’d just have to make sure you’ve got 1.25” clearance (e.g. don’t screw it in right above a drawer).
Of course, one of the things with butcher block is that it’s gonna expand and contract with humidity, so you can’t completely restrict it. But I think that if you use screws that have diameters that are smaller than the pre-drilled holes on that angle, even when they’re screwed in tightly, they’ll have adequate lateral movement.
Disclaimer - I’m not a “carpenter” by any means, but I do nearly all of my own home repairs, and the above is what I’d prob try if faced with your problem.
This. Had a mini since they were released and it’s been a low maintenance workhorse. Prusa adding input shaping, etc. via firmware was just icing on the cake.