I think measuring bpfsl (bone pressed flaccid STRETCHED length) is a good measurement. Lately, if it is 2 mm less than my max measurement, I take it as a indicator to wait. Sometimes, if I wait 36 hours instead of 24, it makes a very big difference.
But as has been said here, you have to find what works for you. Some guys find if they take a day off, they lose ground. Others find if they don’t take a day off, they don’t gain. There as been more than a few guys who found they gained at 2 on and 1 off, but when they went to 2 on and 2 off, they gained even faster.
So, experiment and see what works best for you. I would recommend to start to take bpfsl, because it really does give you a lot of good information…and keep a PE log.