I echo what others using ovens say, time is not as critical as you would think and its all about finding that sweet spot between time in oven and temperature. Its a bit like any dye sub method. You can often reduce the time and increase the temp and get the same results. The higher the temperature the bigger the risk on things like ghosting. My oven fits 24 mugs at a time, that takes between 16-18 minutes. When the timer is done I take them out, put another 24 in and only then I remove the wraps. Sometimes I have waited 5-10 minutes before removing the wraps if I am distracted etc.Could I jump into this thread and ask those that oven sublimate how important or quick you have to be to remove mugs from oven once time is up followed by removing wraps and then paper from mugs if you're doing 12 at a time? With mug press then we remove single mug and paper within about 5 seconds of end time to get under fan otherwise sublimation still occurs and print over bakes or ghosts (double print if paper has moved). So with 12 in an oven then I imagine our process wouldn't be viable.
Which brings me to say that you might want to look at your times and temps in the presses. I have (and still do) use single mug presses and for a fair few years used a five at a time mug press. I never dunked the mugs in water and once I found that sweet spot between time and temperature I never got ghosting. In theory your mugs should stop "printing" almost as soon as they are removed from the heat source. The only reason they would continue is because the temperature is possibly too high and allowing the ink to continue. It might be worth reducing the temp and increasing the time.
Please do not think I am trying to tell you how to do your job on your kit, you know better than anyone what works for you, just a friendly observation :-)