Never had legit jerk... That said, I love the style. I think the guys pointed you in the right direction, think wood fired grill not low and slow. From here, I believe the actual jerk technique varies on the protein. I make jerk pork in the traditional manner with wet marinade and cook. That said, I use a fresh made wet marinade and prefer it over WW. The wet marinade I make has an intense flavor compared to WW. The finished jerk pork takes on a very rich near almost steak flavor. Not sure if that is legit but I sure like it. I prepare like they do. Pork butt cut into strip for maximum marinade penetration and take IT to 200 or just under FOTB and chop. FYI the marinade is hot as a MOFO (still tasty tho) but there is very little heat in the finished product. I suggest you play with pork for awhile first.
Only made jerk chicken once and it was also a fail HOWEVER I have really studied it and plan to run some soon. I have a few GOOD books and also read LOTS online... My thoughts on jerk chicken are that is made not like jerk pork but similar to american BBQ. Dry brined and once near cooked apply the jerk sauce liike typical BBQ. I think WW might work as a sauce here but I plan to make the marinade and cut it with some ketchup.
WRT to piemento. I don't think it is really a secret weapon. I have "piemento" pellets and while they are a blend, it's still a strong smoke. I'd say 50:50 apple:mesquite would be pretty close as a substitute.
Here is the dry jerk mix I plan to use for chicken and also her book that use to make the marinade:
Lastly... I know there are some Kiss fans here and saw this today. Seems strangely relevant