They have clamped down on rapid reinstatements.
Expect at least a year of diligent meeting attendance, making sure you have lots of highighted colors in your WT and study books, saying all the right things in the JC to reinstate you.
And that's if there is not a personal grudge of some kind against you by one of the JC members. If the JC (or any one of them) was making an example out of you for whatever you did -- they can hold out for A LONG TIME and ONLY the original JC has the authority to reinstate you, regardless of where you attend now.
The idea of readmitting someone because they have great potential as an Elder is BS. That would mean you threaten their position of power as well (if you are in the same Cong or even the same Circuit). If you are smart, you are a threat, you are pompous, you think too much of yourself, etc etc. They can find the "reason" to hold you back.