My use of Emma is comparatively simple compared to the OP.
I use it primarily as a quick way to get overview of all my accounts in one place (I have accounts with 7 banks and credit card providers). To improve this use case, I’d really like for Emma to provide an all accounts screen where accounts were grouped by bank. Ideally I’d like Emma to replace the need to have first-party apps from most of my banks and credit card providers on my phone, but we’re not quite there yet.
I also use the transaction notes feature a lot. I do like adding notes to transactions I think may be important for me to remember in the future. I only have one bank for which I can do this natively (Monzo) so for other accounts this is all done through Emma. It’s slightly limited in Emma in that notes can’t be added when a transaction is pending (which is when it would be most desirable to add notes) so if the team could figure out a way to add notes when a transaction is in pending state, I’d be very happy!
I do use the categorisation a bit but I’m happy with a broad overview of spending and not really interested in high granularity. So I’m happy with Emma’s default pre-defined categories.