Sonos app constantly running

In desperation I download a third party app. Macronous for Sonos. It's a bit strange but once you get it, it's easy to control volumes, rooms, what music, and for me the best thing from favourites. There are some radio stations where the skills are messed up so Alexa can't find them.. a working app is a must.
Best of all, after 3 hours of use Macronous for Sonos doesn't even show up on the battery usage list!
It's used 3mA according to the app data.
Come on Sonos!!

I've been discussing with them on messenger. Very responsive..
Yes, the more the merrier! They're ignoring me on Twitter and Messenger!

The Macronous for Sonos app uses no juice to speak of. Had I running all day in use and in the background.
Granted it can't do all the Sonos app does, but how could Sonos get battery management so wrong?

I got pretty much the same response as you - I did a diagnostic and sent them screenshots of battery use. 200mAh in 3 hours, so not quite as greedy as yours. They suggested I should Force Close the app when not in use. I did that, but it made no difference, the app is still gobbling power so I told them that and they haven't replied since. In the past three hours I've used the phone for nothing but screenshots of battery usage and Sonos has used 9%, the screen 3% - Sonos was in actual use for around one minute at the start of that three hours, but no music playing. Think I might have to lash out and buy Macronos.

Yeah, I've worked in major telecoms SW dev and testing all my working life!
This sort of thing just shouldn't happen! Any Tom, Dick and Harry third party app developer can get power management across different OS versions right!!