As far as Harrier input goes, I think that the situation is the same as with the Hornet community. That said, I see a few wrinkles with Jarheads advice. It's not "wrong", but there are several ways that it can backfire.
First of all, recognize that whenever you leave the community for any length of time you risk not being able to come back. It's a pretty low risk, but there nonetheless. The longer you're gone and the fewer quals/hours you have, the more risk.
The days of going to the training command and returning as a captain are over. Used to be the standard way back in the day. So this is really a question of how majors get orders to the fleet.
As a general rule majors are on a DIFOP/DIFDEN alternating cycle. It's pretty hard to go back to back in the cockpit, though not impossible. Pretty much the only way to do it is to convince your monitor that you need a department head billet for career progression. He may or may not buy that. Each year there are X number of majors billets in each MAG and Y number of majors trying to go back. The number one criteria that the monitor uses in each case is DIFOP status. What you're essentially saying to the monitor is that "I deserve to go straight back to the fleet before one of the other guys who just sucked up a tour out of the cockpit because of (fill in the blank)".
The other guys have the same department head requirements that you do, so that's a wash. What else do you have? WTI?A personal request from the MAG CO? Pictures of the monitor playing golf with Satan?
It'd better be good if you are going to "cut in front" of other dudes coming off DIFDEN orders. Of course, you might get lucky and the MAGs need more majors than are trying to get back there, which happens sometimes, but I wouldn't count on it.
The best plan is to ask for what you want, but have a backup plan that will work. Here's where I see risk with Jarheads plan: the monitor ONLY cares about your DIFOP status. He could give a shit if you flew a single hour or not. DIFOP is DIFOP. If you are at MAW or MWSS DIFOP, then as far as he's concerned, you flew as much as a squadron OpsO. You will not. Not even close. It may be advantageous to ask for DIFDEN orders in order to preserve your chances of getting to actually fly next time around. Otherwise, you could spend two years or so DIFOP, then get orders to DC with about 30 or so hours to show for it.
If you end up getting DIFDEN orders out of your VT IP tour, there are other ways to mitigate that. Have a reasonable "bad deal" plan to propose to the monitor. Regimental, Division or MEU Air Officer or TACRON are fairly quick turns back to the fleet. So is resident PME, but that's looked at generally as a good deal, so it could backfire.
Having fleet quals will help your case, but those are more or less assumed if you are going to be competitive to come back. By that I mean section lead as an absolute minimum, but more realistically division lead is assumed. WTI is a great card to play, but they don't often send them to the TRACOM anyway. Being an LSO (advanced or training) helps, but ALL of your quals will need to be refreshed anyway. It's easier if you already held them.
FWIW, here's what I did:
4 years in the fleet.
3 years as a RAG instructor
1 year as a Division Air Officer (Okinawa, unaccompanied)
1.5 years as a Department Head in the fleet
2.5 years as an MWSS XO (DIFDEN by request)
Currently on station staff (DIFOP) flying C-12s.
I would have never gotten these orders if I was DIFOP at MWSS. I'd be rockin a cubicle in the five sided wind tunnel right now.
There's nothing wrong with going to the VTs. Just know that you may have some trouble getting back to the fleet. If you definitely want to be a 20 year fleet guy, don't take that risk. Take a FAC tour or EWS and come straight back.
Good luck.