Look at kegals like push ups.
You could train for endurance by doing hundreds a day or
you could train for strength and have someone sit on your back.
Or you could mix it up by training for strength and endurance.
Remember you are training a muscle. Muscles get stronger when stimulation is balanced with rest.
The closer you get to kageling to failure (when you can do another, or can’t hold it any longer) the more rest you need to recover.
So you can do a set when ever you think of it all day, provided you don’t really tire yourself. That is, quit when its still fairly easy.
Or, you can do a couple sets to failure, and take a day or two off afterward.
I personally like to kagel for strength of contraction. I will get a partial erection of about 50-80% and squeeze it with my hand. I then kagel against that pressure, kagel and try to hold it for 10 seconds. I will do as many sets as I can, with about 15-30 second rest between sets.
I know when to quit, when I can no longer hold the kagel against the pressure for the full 10 seconds. Then I stop the exercise. I wait 2-3 days then do it again.
You will know that you are getting stronger when you can either do more sets, or the same amount of sets against a stronger grip pressure.
The proof will be in stronger, harder erections ( as long as you are not overdoing the other PE exercises).