You'll notice that the instructions on the bottle say it will dry in 20-30 minutes but that a second coat can be applied after 24 hours. I split the difference and always leave it for at least 12 hours before I do any work on it.
I find that I can apply decals and water based washes after 12 hours with no problem at all. I leave it much longer, at least 24 hours, before applying oil based filters or similar, having had a bad experience resulting in a somewhat over weathered model by trying to rush