This is a brilliant route, although i wouldn't bother stopping at the pub in the village at the start of the return leg (sorry, can't see the name on that map or get Google maps to work to find out), the landlord is a total c*ck and very anti bikes 👿
I would actually avoid the hike up Brown Trousers (Y Das) as it doesn't bring anything useful to the table. Instead, when looking at the map, there is a bridalway to the left of Y Das that is rideable and pops you out at the same place. You'll need to start at a different location though.
Oh, I also recommend doing it when there is a gale blowing 😳