No, I find it causes a zombification effect when taken long-term. That is, instead of having natural desires and thoughts, it feels as though I have to think about what I want to do. And even then everything feels like work. Basically it kills spontaneity.
Also, I had a hard time balancing methylfolate with vitamin B12. When taken long-term something called methyl trapping can occur and vitamin B12 is needed to correct it. But, you need to find the optimal dosage and scheduling of B12 alongside methylfolate to get the most benefits. For me, I could never get it down right and would find myself in a roller coaster of good days, meh days, and terrible days. Actually, the good days become rare in the long-term.
Plus, you also need to ensure that the other vitamins are in optimal levels. The vitamins used in neurotransmitter production, like Vitamin B6. Or at least in my case it was. Too little of those vitamins and the methylfolate does very little, too much and my cognition worsens considerably. Finding the optimal level felt impossible, as though it was a thin line between those two extremes.
Have you seen the longecity thread made by the user Chadwick? He's been taking it for a long time: https://www.longecity.org/forum/topic/64835-chronic-dopamine-deficiency-consistently-disappearing-during-alcohol-hangovers/