I live full-time in Thailand and would welcome a bike in the 350cc class from ANY manufacturer.
Big bikes are starting to sell quite well here but their prices can be extortionate; imported bikes can cost twice as much as the identical UK model - eg. Bonneville equivalent to 13.5k GBP, Street Triple R 15k GBP, Rocket 3 Roadster 27k GBP - so I'd only be interested, really, if it were made locally with a correspondingly low price.
Rogerborg says " .... on one Rip Off Britain bike." - still think UK's a rip-off for bike prices, Rogerborg????
Since Triumph already have a factory here, I think a 350 Triumph WOULD be locally-made and I hope they'd have the sense to negotiate good deals with the Thai government regarding prices. Triumphs made here at the moment have to be exported & re-imported again so attracting the higher price. Stupid, but that's the way it is. There's a demand for Triumphs here but not at the crazy prices quoted above.
In my part of Thailand, at least, most roads just aren't suited to big bikes IMO, due to their poor condition. The only place I see big bikes is on the main highways between cities, where bends are rare, never on the rural roads. I can have great fun on rural roads on a 250 but would be pushing my luck on a 650 or bigger. A sporty 350 would be ideal. Thai road users aren't used to bikes travelling at much more than 50-60km/hr and tend to have slow reactions where bikes are concerned. You think UK drivers are inconsiderate? You'd have nightmares here!!