Folinic would be an improvement over folic acid, unless you're one of the (I think fairly rare) people who don't process folinic acid well. Methylfolate would be best.
The next part I'm confused about. I'm not sure if he's referring to taking a more specific MTHFR test, so you know whether it's C677T or A1298C (or both), or some kind of folate test (as a checkup to see how the you're doing with the folinic acid?). Maybe he doesn't remember that you already had a low folic acid test?
If you decide to try the folinic, my suggestion would be to start with a fraction of the pill first to test your reaction. Also have some niacin on hand in case you start feeling worse. The article from Ben Lynch below explains how to use the niacin.
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Here is another article from Dr. Ben Lynch on possible reactions from methylfolate (could also apply to folinic):
http://mthfr.net/methylfolate-side-effects/2012/03/01/