Here’s GOLDFINGER, the literal pure gold, finger wiggling, signal routing & mixing matrix mixer from Music Thing Modular. It has 6 bidirectional connections (so ins and outs as you choose), its passive and routes and mixes signals depends on what parts of the surface you touch.

Here’s GOLDFINGER available direct from Thonk // https://www.thonk.co.uk/shop/goldfinger/