Stick it out.
19-seat TP guys with 1500-2000 hours turbine PIC are getting harder to find these days and the big guys like to hire guys with 19 seat TP time. One major airline chief pilot told me that if they could (this particular airline), they would only hire 19-seater types.
They know that you will not flunk out of training since you have been flying w/o an autopilot, and probably have a stellar instrument scan. They also know that you won't complain about doing more than 4 legs in a day, or going above and beyond since that is what you do every day.
Besides, if you leave, the recruiters will look down on the fact that you aren't willing to stay at a job for very long. They will think you do not have any commitment to your job, lack motivation, and will be very worried about your commitment to them.
You have a chance in a lifetime to upgrade right away and get the time you need to go to a major. Don't throw it away, only to rot in the right seat of an RJ for the next 5+ years. They can never take that Turbine PIC away from you.
Think about it.
J32
p.s. - The market for regional jets is starting to shake-out. If you have your heart set to leave, be very careful. You might wind up owing GLA $$ AND being furloughed.