Yamaha receiver volume options

Hey all, any way I can set how much the volume goes up or down when using the OpenHAB app? It appears to jump the volume by 10% up or down with a button press which results it quite a significant change! I’d like it to step only 1% so I can hold the up or down button to increase/decrease slowly. Is this something I’ll need a rule for? Seems something that should be enabled in the binding itself.

OH 1.8.3 FWIW.