Hi Bitsa good to see you found it.
It funny I've been using the Triumph the last couple of weeks and had exactly the same thing
I noticed oil on my boot looked at the back of the engine to find oil over everything

So I decided it was the rocker cover gasket so I striped the bike down thinking it was going to an easy fix only to find I had to drop the engine so no biggie remove rad,exhaust and a couple engine mount bolts whats hard about that.So with the luck I have it goes wrong almost instantly I undone a couple of studs with ease the third one ping snapped instantly So a trip to the dealers.I come back seal the rocker cover place the engine back in and ping the engine mount bolt striped it's thread.So two days later back down the dealers come back push the bolt in I can't find a nut to fit

anyway I've used it this week no leaks until to day I pulled away it's like a two stroke blue smoke so just pulled it apart again to find the air filter box full of oil so a bit of head scratching I noticed oil drip from the crankcase breather BINGO found it the breather seal split.
Regards Thread hijacker