(Denon AVR) Amplifier - Volume control not synced - Values are wrong

I’am using the Denon platform (the networked one) like this:

media_player:
- platform: denon
host: !secret denon_ip
name: Denon AVR 3808

I want two have a slider or a horseshoe control to adjust the volume. This is possible but i have

  • 0 - 100 % as Value in HA for the volume
  • stepping 1 %
  • no sync of volume after on/off of the AVR

This leads to accidently very loud sounds when touching the smal slider on the phone after a restart of the AVR. HA shows always 100 % after that.

I want to archive:

  • min Vol.: - 80,0 db
  • max. Vol: + 18,0 db
  • stepping 0,5 or 1 db
  • Synced Volume in every situation

Can one guide me in the right direction to get that? Or even better: has someone solved that and can help me with his solution?