To reduce mouse hand travel I got a roller mouse pro slim about 6 months ago. Not great for fine motor tasks but exceptional for other general uses. Alleviated a lot of pain in my hands and fingers.

I use this with a small slim keychron keyboard and with a kinesis advantage 360.

The roller seems to be getting a bit sticky after 6 months of heavy use and transporting it between work and home. Nonetheless, would get another in a heartbeat.

Perhaps worth a look?