Schematic - Modular trivets

I have a little set of hexagonal oak trivets I made for for glasses.
The thought occurred to me that with magnets, they could assemble in a nice pattern, to support larger pots.
I could also etch them with occults symbols and runes to assemble sephiroth or qliphoth patterns.

The wood must be sturdy and resilient to heat, such as oak. What I fear is using glue to fix the magnet, for my previous experiences with glue has mixed results... Maybe a little offset in the carving would reinforce the fixation, but it will be tedious to grind.

pencil doodle on A6 sketchbook