I'm not so sure the pressure itself dictates the whereabouts of the carp, it's the conditions that comes with the pressure systems. Periods of high pressure will (normally) see sunshine which will see the carp nearer the surface taking advantage of the heat. As soon as that sun goes down you're quids in for a bite off the deck towards dawn regardless of pressure, particularly at this time of the year when the water's still warming up.
It's different in winter. For long periods it's not comfortable for carp on the deck due to the coldest, densest water sinking to the bottom. Therefore they'll likely be mid water most of the time regardless of pressure, and that explains why feeding periods on the deck can be so short in winter.
I really struggle for confidence with zigs in coloured water. By all means try methods to attract the carp, chances of a take without it are low IMO.
With 3 rods each we really need to be making the most of our options. I find, in general, in really high pressure you'll struggle for a bite in the day anywhere in the water unless a hatch kicks them into action. Zigs are your best bet though. Once the sun goes down you can get action on the bottom or on zigs until about 3 or 4 am, then it's all about the deck until 9 or 10 am. Then back onto the zigs.