Yea matts approachusually helps people on extreme diets get over their ED but it doesnt really fix smaller issues like hypo/digestion because its too vague. I also dont believe fruit to be cooling unless its all you eat and dont eat any salt/drink tons of water.
No you dont have to journal if you dont want, its time consuming and stressful. I think you should write out a plan and then follow it for a month straight and then reevaluate. Take detailed before/after marks and maybe follow trends like weight/temp/energy.