I've only done one TT before - an "invitational" where anyone could turn up and ride. So I turned up in full Audax mode complete with mudguards, hub dynamo, rack pack, multiple front and rear lights, radio, etc.
Personally I hated it. Far too much like exercise for my gentile nature. However I'd be happy to flog myself half to death to support your enlightened event Mr Teeth.
Have you organised preferential repatriation rates for The Fallen during the event?