I remember Ed Bennett trying to get you to see the light not to long ago. If he couldn't help you, I haven't a chance.
I am not really asking for help, you asked for the explanation. I explained it.
If you need to use a dial indicator to give you the confidence to set up your cuts then be happy with that method. Every one has their preferred method. For me simpler is better, set up the equipment correctly to start with, buy only equipment that performs as required and trust that equipment. If you don't trust your equipment, adjust accordingly. I personally do not need the dial indicator to make accurate cuts. It is a good tool to have around but I really don't need to use it that often...at least in the last 10 years.
Using a dial indicator to set up cuts reminds me of when I used a tape measure to verify my fence setting from the blade. Now with better equipment I totally trust the markings on the fence rail, the markings and machined index holes on my Kreg miter gauge and both of my Dubby miter sleds. I get results that I believe you would agree are perfectly fine.
Ed has a good product, but seriously, the more ways he can teach one to use it the more likely that he will sell one to some one sitting on the fence while trying to make a decision whether there is a justifiable need to buy. I still nave no need as I do have a dial indicator and don't often use it. If I were having trouble cutting accurate joints I would probably upgrade to Ed's version of the dial iindicator.
I certainly do not need a Festool Domino for making mortises, I have a mortiser, but I wanted one and enjoy using it.
What's that Texas saying, "You can bring a horse to water, but yada yada yada." :^P
May be the old saying,,,,with time and experience comes knowledge.... ;~)