HomePod volume keeps resetting to 65

As identified originally here, HomePods automatically change the volume to 65% after a certain amount of time, if the volume is greater than 65%. I’m just now discovering this horrible feature. I use the HomePods for whole home audio and broadcast music to it via my Windows PC using Tuneblade. I control volume via my media player running on my Windows PC. If my HomePods volume is not maxed out, I don’t have enough range to control the volume effectively on Windows. This is a deal breaker for me.

I have attempted to set automations to max out the volume via my iPad home app. The automations work temporarily, but invariably the HomePods revert back to 65%. I’ve also turned off the adjust Siri volume setting which has no affect on this.

Does anyone know of a way to keep them at 100%? If not, does anyone know if the HomePod V2 also has this issue? If so, are there any other high quality AirPlay certified speakers that don’t have this issue?

thanks!