Like Dave I used to put a spot of R40 in my triumph twins in years gone by, but it used to make a mess of the inlet valves you would get a load of horrible snot on the backs of the valves.
I use Mobil Extra Semi Synthetic in the H2 - been told that fully synthetic is a waste of time because the engine does not get hot enough and you will end up with a lot of deposits in the engine.
I also used to use the same in my MZ, and burns pretty cleanly.
If you really want that smell you can just put a spot or two in the tail pipe by way of a syringe.
Just stick with whats best and intended for a 2T.