This thread may take off soon lol, the diesel additive debate lol.
I don't believe marvel would do any damage to a system but I also don't think it would do much good, the quantity you would use would get expensive.
I have a 05 4320 and I add a small bottle of 2 cycle to the tank, idk if it helps it mechanically but I mainly use it because the tractor is noticeably quieter and smoother, I don't add nearly as much as people say to add, my tank is 10 gallons and I add like a 2-3 oz little bottle in there after I fill up, every time I do she settles down a bit while idling.