Wouldn't Microg solve this?
Discussion
Why would you go back to install Google services on a de-googled device? It doesn't make sense. You wanted to get the fuck out from Google prison and yet you want to go back inside LOL.
Microg is not from Google it's just FOSS reimplementation of its proprietary libraries
And to be frank it's almost impossible to get rid of 100% from Google apps in Android but if you can do it 90% is a good way
Does it do notifications too?
Yes
https://itechify.com/2021/08/03/push-notifications-huawei-phone-microg-services
Or you can try this alternative: