Im heading out that way next weekend but its with a local club so your not invited road bias wont be a problem on certain lanes. strata florida should be ok, its mostly bedrock based. rough in places but mud terrains are optional. Soar y Mynydd is the same. 1 of the lanes out of Rhyader is mostly bedrock too. North of devils bridge, some mud, but can be avoided, mostly bedrock. dont know about brechfa forest yet. The club will be exploring on the monday.
Do a google search for local LR clubs in your area. there must be a west wales one.