Depends on the weather. When we EK98'* during your visit here a year ago, it took a bit longer, even though we dried them indoors.
After cleaning and drying the tails, use a blow dryer to pre-warm them this time of year and get all the moisture off. Spray, then move them inside for 20 minutes between VHT coats. Use the drying technique with the blow dryer again if you wet sand. Clearcoat dry times vary by brand and type.
In the summer, 10 minutes between coats should be fine if they dry in direct sunlight, but I'd give it an hour inside or outside after the last coat of VHT. You don't want it outgassing through the clear while it dries. Another hour before you wetsand and apply the last coat of clear.
The outgassing cost me a set of tails recently. They need to be stripped and re-done as a spare set for my cars now.
My odds are now 7:1 with these techniques (Twice for my SSEi, twice for my SLE, Jseabert, driverjohn2005, EK98, and one failed set).