Controlling Alexa Volume: Volume Range Resolution

I’ve build a remote control for one of my Echos using a Hue Dimmer Switch. It allows me to start/stop the music, go to the next track and to inrease/decrease volume.

Volume control is done with the media_player.volume_up and media_player.volume_down actions of the Media_Player.

Unfortunately the steps are quite large. If volume ist too low, the next level often already is too loud.
I found that the range is devided into 10 steps if you modify the volume via voice or media_player.
If you use the buttons on the echo, the resolution is much better, namely 30 steps.

Any chance to have the same volume resolution (30 steps) with the media_player?