I would consider the time in between each lesson if you are driving another vehicle you will get accustomed to the gearbox, brake pedal feel and clutch biting point etc if applicable and need to readjust each time you go out again. I made a point of not driving anything else until after my test when c and e and i think c also, but was doing two 7hr days sat sun and test mon morning, so not a big sacrifice. Most of the time at present i’m driving a six speed box so when I hop in a splitter it doesn’t take long before I’ve stalled at lights.