I recently imported from Degiro 3 years worth of stock transactions and I have a suggestion to make to improve the software.
In order to make the plot of historical price work, I had to manually select for each asset, the source for the data.
It took me hours but it is done.
My suggestion: make predefined, for all added assets, a specific data source such as yahoo adj. close price. Then, the user can change this if they wish so, however, as it is now, you need to define a source manually and it is a pain.
I can’t vote for your suggestion. Many times the data from Yahoo is so bad, that it cause long discussions here in the forum. And you have to enter the symbol in every security, that can’t be automated always.
But I understand your pain, even if its a one time job: Maybe creating a CSV Export/Import for the data source is a better idea, than you can export, fix it in a tablecaculation app and import it again.