I want to like Kmail, but it's a bit too opinionated (e.g. having a setting letting you set to reply-to-all by default was removed because it is 'wrong', as wel

I want to like Kmail, but it's a bit too opinionated (e.g. having a setting letting you set to reply-to-all by default was removed because it is 'wrong', as well as having the button show up on messages without a roll-down) and just too crashy (akonadi...) and impossible to backup configuration (I spend a full day tracking all the various files/dirs down, no luck). I think there's an A-rate tool hiding in Kmail and Kontact, but development is glacial and not very responsive feature requests. (I even asked for some help setting up a dev env to develop something myself but no replies.)