Meh, depends on the conditions of your character when you betray. If you've got a lot of plat invested in Masters, then yeah -- it'd suck. Just going through the steps, though, is super easy; I just took a ranger over to FP this weekend & it was only about 4 hours total effort. Grinding the writs would be a lot harder than that.
Honestly, knowing that it's possible to keep the titles -- I'm tempted even with the plat I've got in Masters. Hrm. Will definitely have to make a decision soon, though; the last 2 levels have some very pricey Masters on CB.
So how many writs would it take to get Captain, anyway? Oh, & what are the solo FP scout writs available to a 68?