I can share the script on GitHub if anyone is interested. Among other things, it converts funds to their value at the time of the transaction and adds additional transactions to reflect capital gains and losses. This allows Metabase to accurately report net worth over time.

I really want this too. Neither Actual nor Firefly III support stocks/funds (open issues for Actual and for Firefly III.

I use GnuCash for my transactions, which I manually export from my accounts as QFX files. Although GnuCash has support for tracking fund values and generating reports, I do this with a custom Python script and Metabase instead.