The 9th F-C RCT fought on Twycross, when it was retaken from the Jade Falcons in 3050, and according to the old "Invading Clans" book they were later driven off Twycross by the Steel Vipers.
In the 20 year update the 1st, 2nd, 3rd, 4th, 5th, 6th & 8th were in the Sarna March; 10th in the Draconis March; 9th, 11th & 12th in the Skye March; 7th in the St Ives Compact.
In Objectives Raids the F-C's in the Sarna March are still there; while 11th & 12th are still in the Skye March, 10th is now in the Tamar March & 7th is still in the St Ives Compact. The 9th is missing (but there are few units missing in Objective Raids) but it did survive the Steel Vipers and I believe it was used to form the (Lyran) Alliance Jaegers.