I recently replaced all my HomePods with the new Era 100 and 300 speakers. For the most part, everything is better… except audio normalisation. I found some ancient threads on this issue (and also on Spotify forums), so I know I’m not imagining things. I use Spotify but I believe it also happens with Apple Music.
So it’s great not to have to struggle with AirPlay and a whole host of other volume issues that now the lack of normalisation is really the biggest complaint I have now. It’s annoying to have to adjust volume from time to time when playing a varied playlist. When using Spotify over AirPlay, it works fine. Spotify over Spotify Connect doesn’t work right.
I realise this is probably a Spotify issue but perhaps you could put some pressure on them to do whatever they need to do. It’s a feature music players have had since the early 2000s in my recollection (SoundCheck in Apple iTunes).
Cheers
Chris