Allow for multiple profiles in one account
N
Near Marten
Can't you just create a new temporary wallet for your API sync? Eg. if you want to import Binance via API to see what it looks like, create a new Binance wallet and put the API key in. Then you can have that side-by-side with your other Binance wallet where you have imported the CSVs.
Granted it won't allow you to properly sync transactions with other wallets (transfers/withdrawals/deposits will be duplicated etc), but it at least allows you to view and compare the differences between the CSV and API data, then delete the wallet that you determine is not the best choice.