Changing builds can be a hassle. While a developer has stated that this is on purpose, perhaps it would be a better idea to implement it as a gold sink by offering consumables that do the job.
The first thing that comes to my mind is a consumable item that allows players in explorable areas to repec their traits while outside of combat and at a waypoint.
Since convenience has a price, the consumable itself should cost a lot more than the standard 3.50 silver rate when speaking to a trainer.
Another possibility is to make an item that functions similar to the “copper-fed salvage-o-matic.”
This item could save a player’s trait builds and allow the player to switch between them for a price (example: 2 silver per respec).