BFD over MPLS

First time poster here. We have a network running MPLS with LSPs that are protected by dynamic bypass. When a physical path goes down the LSPs utilising that path will go down but the traffic will move to the bypass LSPs (Fast Re-Route). This action takes some time so there is a brief period of packet loss, normally sub-second.

My question is if we have BFD running over L2circuits on the MPLS network what should the timers be configured to so that the sessions stay up while Fast Re-Route occurs? Is setting the timers to a value just greater than the RTT of the L2circuit a good place to start?

Any guidance appreciated. Cheers