Shakey

what is a 'high integrity' board?

anyway, just treat every circuit as a normal circuit, regardless of it being a TT

if a circuit requires 30ma, because its got buried cables, socket outlets, or bathroom, then it needs 30mA, TT has nothing to do with it

so the non rcd protected ways can either be for surface mount cables (or protected cables), and if they still meet their disconnection times then you are ok, if not, just RCBO's

you should do this for your smokes anyway, unless you are gonna surface mount/ or put you lights and smokes on a seprate RCD to the sockets