All good ideas - but I went for simplicity and functionality over any advanced features.
I may add some magnets. Most commercially available plastic and aluminium jaws use them.
Pure Teflon/PTFE is
fairly inexpensive to get - I have paid 10€ incl. shipment for a 10 x 10 cm² piece with 10mm thickness.
I have also thought about dowel pins, but I have skipped the idea as the design is sufficient for my use cases. Not every workshop has the tools for the required precision work.
Admittedly, not every workshop has a miter saw and a drill press, which I had used. Alternatively, one could surely use a router for cutting the lip and a different saw to cut the work piece.
I'd be glad to see improved versions build by other members, of course!
Just keep them coming...
Cheers,
THDplusN_bad