saj42 We love Tasmota too!
The issue is that Tasmota doesn't currently have (to my knowledge) a matrix keypad driver.
It can probably be done with Berry, but it's not something we're actively working on at the moment.
If someone in the community did get things working, we'd absolutely link to it (or accept a PR to include it).
If you're moving away from HomeAssistant to a different platform, it would be possible to use MQTT!