Glad to hear you're making progress.
I've been to sseveral conferences and courses... just keep my eyes out for them, along with a lot of online courses and research. On this topic, I learned from some of Ben Lynch's courses, where doctors from all over shared case studies.
No one used SpectraCell - there's not enough information to work with. Most used the NutrEval - its comprehensive and they solved a variety of problems with it. Lynch and 3 or 4 of the most experienced doctors used the HDRI and pinpointed exactly what's going on. I'd say you need a doctor who can interpret it, but if he/she can and you specifically are interested in methylation, it'd be the best.
I have 8 years of NutrEvals for multiple family members... They've changed over time as we've hit different bottlenecks. It's a very useful test, especially as it goes beyond methylation to antioxidants, Krebs cycle, mitochondrial dysfunction, neurotransmitter metabolites, and toxicity.
I take Thorne Research 1 mg molybdenum daily and have for a couple years, along with 5-600mg benfotiamine and 1g taurine to keep my transsulfuration pathway moving. The NutrEval keeps an eye on my molybdenum level, which used to be low and now is normal.
I also get glutathione, molybdenum, and taurine in IVs, as a support to large doses of methylation nutrients.
Its a matter of getting everything in balance working backwards... Get transsulfuration working, then optimize the methionine cycle, then add folate. Then, as you detox, you'll raise the nutrient levels appropriately to keep making glutathione.
Also, the docs were all using the Doctors Data provoked urine heavy metals test. No one used a hair test....
Keep going on this... it will help you in the long run.