Your problems are with synapse. I had a similar experience with it in 2019. Dropped matrix for a while and started using Dendrite in 2020. It still lacks featu

Your problems are with synapse. I had a similar experience with it in 2019. Dropped matrix for a while and started using Dendrite in 2020. It still lacks features compared to synapse but I'm happy with the performance. Notifications are sorely missing but I think the PR to add them is finally ready to merge. Give it a year or two and you'll have a full featured matrix home server that can run on a raspberry pi.