Every 4 days is great. It’s all about how often you can and how often you enjoy it! Keep it fun and don’t make it a chore and you’ll keep a great yard!
How often are you spraying your growth regulator? Your lawn looks like it has that tight regulated appearance. I am surprised that you have to mow almost daily.
I always find I get a cleaner result by edging first, blow, now, and blow. I know it’s maybe extra steps but it’s what has worked for me. How do u set the reel to bedknife adjustment on the Cal?