Portfolio Performance import: unwanted market-data dividends, and valid dividends left out

I'm importing my full history with the Portfolio Performance importer ("All transactions" JSON). My file already has every dividend I received (1,263 in one broker alone). I found two problems:

1. 521 extra dividends "from market data", with no way to turn them off. The review screen says it will add 521 dividends "your file doesn't list". My file does list them. My broker books dividends in the local currency, net of withholding tax, and sometimes a few days after the payment date. My guess is that the app doesn't recognize them as "the same payment", so they would be counted twice: extra cash in the broker and inflated returns. The screen also says it will add splits from market data, and my file already reflects those splits in the share quantities.

Request: an option to skip market-data dividends and splits when the file already has the full history.

2. Dividends left out with "You held none of it on this day, so it does not apply". 17 dividends were left out this way. In some of them I did hold the position that day. In others I had already sold, but that's how dividends work: the dividend goes to whoever holds the shares on the record or ex-dividend date, and it's paid days or weeks later, sometimes after the shares are sold. The money did reach my account. Leaving it out understates the broker's cash. In one broker the import ends with negative cash for exactly this reason.

Request: when a dividend comes from the user's file, import it as it is, without checking holdings on the payment date. If a check is needed, it should use the ex-dividend date and not the payment date, but I still think there maybe should be a warning, allowing the user to import anyway.