You could check out the Motoalliance Firestorm heater, just installed one yesterday they are pretty compact compared to the Polaris heater and work very well.

https://www.motoalliance.com/UTV-Under-Dash-Cab-Heater-RZR

 

https://www.sidebysidestuff.com/upi-cab-heater-w-defrost-polaris-rzr-xp-turbo-dynamix.html

 

that one is specific to the Dynamix and has a relocation plate....Im considering it for ours. Not sure how the relocation plate would affect any functionality hopefully it doesnt

 

well just read your first post are you saying you tried that heater and it didn't work?