Then you're doing something wrong.
Scaling, debugging, refactoring, customer support, prospect interaction, and even raising investment must all be done in support of product development, not instead of product development.
I am a notorious single tasker who loves coding more than anything else, so I used to have the same problem. If some other task took priority, all product development stopped.
Until a artist friend of mine told me the secret of his success, 4 words I have never forgotten, "I paint every day."
Now I code every day. No matter what else happens.
With 3 of you, I would expect that at least one of you could keep building something every day without any of you dropping any of the other eggs you must juggle.