Can't you increase the volume of DStar to YSF via Transcode Gain Setting? It's too quiet for me. Do you have to go to +? How far does the area go?
Please see the user manual: https://manuals.sharkrf.com/openspot4/en/settings-page.html#transcode-gain-settings-openspot4-pro-only (Transcode gain settings section). Valid gain range is -32 to 32.