Say something like "I no longer run an agency, I do positioning work for founders now" and GPTree updates what it carries about you. The version that was wrong stops being used, and you do not have to repeat yourself in the next chat.
Only what you write counts. A description GPTree gives of you in one of its own answers is never saved as a fact about you.
You can still see and edit everything it remembers in the Memory Inspector, and GPTree can now revise your default persona when you tell it that it describes you wrongly.