When I travel London-Ipswich, I normally split at Manningtree in order to use my Network Railcard for the London-Manningtree portion. Tomorrow there is a bus replacement between Billericay and Ipswich. There is a non-stop bus Billericay to Ipswich (I don't want to use the slower bus via Manningtree). Will a Manningtree split be valid on this bus?