Only take note from official lineage os site on compatibility.
You could try divest os or /e/ project.
You could also try getting stock android on the device which doesn't have any google services ( android by itself is free and open source after all.
I get like a few notifications a day, mostly just ntfy notification from all my autotion script telling me was something successfull or watchtower thelling me what docker container was update so that I know that it is cause of the update that something started behaving wrongly.
Everything else I ignore with passion, even have notification sound's and vibration turned off for specific app's so I don't get sound or vibration even if my phone is on full blast. Help's a lot.