Yes, the max load stated by Jobo is 600ml. If you run a multitank 6 with 8 X 120 rolls, you have to have about 800ml of liquid in the drum.
Years of use make it safe to say this is fine. If anything, it may shorten the life of the motor, byt such and such %, but if you think about it, if you run 4 rolls, in two runs, you are using the motor X2 the time, albeit with less load. So at the end of the day it does not make a huge difference. The electric motors are easy to replace, and if you feel like it, they can be rebuilt.
As someone mentioned here a few weeks ago, the CPE2+ motor is a generic bosch motor (so is the CPE2) that is readily available for under 30$ on ebay. (the CPE2 motor is less common but still easy enough to find, new ones are expensive).
The bottom line is that users exceed the max load routinely as it is much more productive, and though i do not have a statistic about the life expectancy of the motors i doubt you will find a major difference.
Expert drums can only be used on the larger machines. This one of the advantages of using the larger machines. Another is the ability to use large print drums (2850, 3063 and so on).
Yet another reason to get the larger machines, is the ability to run larger capacities per run as you can load longer tanks (double or more the motor load capacity then CPE2).
To do 8X10 in CPE2 you can use 2830/2560/multitank 6 (all are the same) drum with the chemical beaker light trap baffle (not the funnel) for up to 2 sheets per run (with as little as 200ml), or 2550 for 1 sheets at a time.
