Portfolio Performance import: market-data dividends duplicate mine, and valid dividends are left out

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

1. 521 extra dividends "from market data" duplicate mine, with no way to turn them off. The review screen said it would add 521 dividends "your file doesn't list". My file does list them. My broker books dividends in local currency, net of withholding tax, and sometimes a few days after the payment date, so the app doesn't recognize them as "the same payment". After importing, the broker's cash is far higher than the real balance, because each dividend is counted twice. The screen also says it adds splits from market data, and my file already reflects those splits in the share quantities.

Request: an option to import my file exactly as it is, without adding any dividends or splits from market data. My file is my record; the app shouldn't change it. A review list to untick them one by one could help some users, but it doesn't replace a simple switch to leave the import untouched.

2. Dividends left out with "You held none of it on this day, so it does not apply". Several 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.

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.