Yes, I agree with what you have said here.
Low iron is a common cause of restless leg(RLS), dizziness, headaches and even anxiety.
It's important to test that iron isn't too high (because that can cause issues too) but I agree that for iron levels test - even when in the low range of normal - it can still cause these symptoms. I have read that Ferritin levels under 40 can cause low iron symptoms.
There is a differnce between bio-available iron and bio-UNavailable iron (RUST! ) , Bio-unavailable iron (oxidised iron/rust) can get stored in the liver and organs and cause issues.
Bio-UNavailable iron may also block avialable Iron from being absorbed.
So it may be beneficial to excrete any bio-Unavailable iron from your body. IP6 (extract from brown rice) is the best supplement to detox oxidised harmful iron.
Organic Unsulfered Molasses is the best iron supplement. 1 Tb morning and night.
This is my opinion
A few nights ago I discovered I couldn't sleep due to restless leg syndrome. Looked it up on the net. Some said take iron. I realized I had not been taking the iron I use to supplement since I eat very little meat. It had gotten lost in the shuffle with my other supplements - didn't replace it when it ran out. Well, I kinda megadosed on the iron. The next night, no more problems. Once before I had problems with low iron, dizziness, and supplementing made the dizziness go away, though my blood tests said I was fine. I prefer to be my own diagnostician when possible and go by symptoms. You can't always count on those blood tests when they say you are fine. I've discovered that in several ways. Plus a doctor I used to have, decades in practice, told me that today's blood tests call "average" normal. But he said 30 years ago people were healthier and "average" really was normal. So, be sure you are at optimal, not just normal/average levels in iron and other things.