My 06 has the same problem I called a dealer who contacted triumph and they told him if he can make it pop out they will take care of it. In the next week or so I will be taking it in for them to have a look see mean while take first to about 3 k and you won't need second just double shift by it. mine I can use second to 1800 without any torque and the shift to third.
Since "It has always been tough to find neutral and occasionally it would pop out of first gear. ", perhaps it is something as simple as a linkage adjustment?
May be worth a look.