Did something similar based on Metabase for the UI.
Transaction stored in a basic Postgres table and regex on my bank transaction export for categorisation.
Facebook almost always has a long-term holdout group in experiments like this to make sure that any gains from the design change aren't just short-lived blips from the novelty factor that ultimately result in long-term regressions.
I understand but, they announced that it would disappear in September. We are at the end of October.
Considering the feedback, I'm quite happy to be still on the old version.