FWIW, the 30 wt is a lower viscosity than the 40 wt BRP states to use.

If your friends clutch survives it is likely from not getting the plates hot. Heat attracts moly. The moly binds to the surface. Moly is more slippery than Teflon.

Seems risky to save $20. Mobil 1 motorcycle oil, 10w40 Sportbike is more expensive, but inexpensive compared to needing clutch plates. The moly is good for everything, except the clutch plates.

So to answer your question, no, I have never run friction modified oils in any of my wet clutch motorcycles.

FWIW, cost vs cost, your buddy could run Shell Rotella T6 in 5w40 for about the same price as Mobil 1 car oil, maybe even less, plus it is wet clutch rated.