@
Plasnart if thats what he is telling you i suggest finding a new motorcycle mechanic.
as to doms original question yes 98 octane will allow for a much better compromise setting between petrol and gas, as for remote travel you can get pretty potent octane booster additives which could be easily carried to give regular 91 octane a bump up if required
the rb30 is/was designed as an unleaded engine (being an alloy head it has to have hardened seats) so is fine without the upper cylinder lube
if you want to get the most out of it just bump the timing up on petrol until it pings under load then drop it back down by a degree or so