I made a suggestion in the forum to
Modify the Investment Performance Report to Optionally Exclude Fees. In the latest release (R25.10) a change has been included which nicely addresses that request:
Improved: Added an ‘affects investment performance’ flag at the category level to filter transactions for the Investment Performance (IRR) Report and in the Growth of $10k graph for Deposits and Withdrawals in Investing.
I've just been testing out the change by comparing the results it produces with those I manually calculated for the last financial year, and they agree exactly.
So a big thank you to the Quicken teams for addressing my request, it will make my life a lot easier!