I would be interested to see magnetic clasps supplied with the magnet unfitted.
That way the clasp can be soldered to a chain without the heat ruining the magnets.
The magnets can be fitted afterwards with glue or drawing a metal bead up.

I have found quite a few of the older generation like these claps as they are easier to handle with arthritic fingers, the weak point though is the unsoldered jump ring link to the chain.