My routine is based on experience. Others may find things work differently, probably a lot depends on your water. And when your guy from the manufacturer of BTF iodophor joined us a while back, he mentioned the part about alkaline cleaner residue and iodophor, so I believed him.
And what's the purpose of StarSan if you aren't actually sanitizing?
If it's the acid product that's on hand, it's good as an acid rinse. I personally use dairy milkstone remover as the acid cleaner and rinse in my brewery, because it's dirt cheap compared to phosphoric acid + surfactant products of identical composition marketed as brewing supplies, but Star San also contains phosphoric acid and surfactants. Iodophor is my sanitizer, but it needs to be preceded by an acid rinse after alkaline cleaners anyway, as any alkaline residue will affect its effectiveness. Again, white vinegar will work as a rinse too, but lacking a surfactant, it may be less effective, requiring a full soak.
In my opinion and experience, that's unnecessary overkill. Simplify...get rid of stuff that doesn't really matter. Reality often astonishes theory.
I encountered beer stone in my kegs after a decade plus of use - I soaked the kegs in milkstone remover for a few days and the beer stone was gone. I would not have noticed the beer stone, had I not had an infected batch that caused me to inspect fermenter (a stainless kegmenter) and dispensing kegs with a bright light and feeling the slight roughness on the inside of the vessels. Scrubbing did not work entirely, so the acid soak was done and it worked perfectly.
I think the level of beerstone might be based on the water composition, time in the dispensing keg, or the typical beer style - but that is just a WAG. It is possible that the kegs came to me with some of the stone in place, but I have no way of knowing, as I did not inspect them that closely when I got them - I cleaned them thoroughly and used to break them down totally each time, but I did not notice any stone until this past year. Now they are clean as a whistle.