The Lucas MSDS doesn't reveal what's in it. Do you want to add something not knowing what's in it? Why would you add something that doesn't bring anything to the table?
The "regular "stabilizer is nothing more than thick oil, a viscosity of about 110cst, a very thick gear oil.
"Lubricating oils,petroleum,c>25, hydrotreated brightstock based"
The synthetic version is supposed to be lighter, about an 80w gear oil. But no moly, calcium, boron, anything to improve, enhance, sustain, or better the lubricating properties of oil.
There are better adds for your dollar.