I prefer not to use my profit because it's already a profit, with your initial balance, it's better not to use it so you can play in peace. I think it's better when your profit is already above the initial amount or equal to it meaning if you deposited, 0.1 and when you gambled and made it to 0.2, and I will withdraw already the 0.1 profit and play again with my initial bet.
I understand what are your logical thinking about profit, But you can't say that you already seperate your profit once you came back gambling because once you lose, Even if you use only your bankroll. Then it might consider also that you lose to your profit because your gain status is on losing.