If you are running two 0.7mm jet without accumulator or push pump, you probably only see a small flow increase, 5-10% at most. When you add a small accumulator, the aquamist pump will instantly add anothe 10% of pressure and 10% flow, it is due to the "fly-wheel" effect, pressurised water is being stored during the exhause stroke and release duiring the pump's intake stroke. The accunulartor fdoes have to be very bigm anything over 20cc will do, this is due the rapid cycliing rate of the pump (50 times per second).
When you add methanol to water, you need to increase the jet size by one step or two, due to the lower latent heat of methanol. Adding a push pump see below:
http://www.aquamist.co.uk/phpBB2/viewtopic.php?t=127
This is a very cost effective way to increase your flow and help the efficiency of the aquamist pump especially if you have the water tank in the trunk.