i run my white to my jv3 160sp through and auxiliary line. with cleaning solution running straight as the common fluid. i run white about three or four times a month. when i do, i run white a for the entire day.
couple pointers if you are going to run white either standard or auxiliary. transfer the white to a clear cartridge. it is difficult to "shake" mix the white without a visual reference of how well you are doing. with the clear cartridge you can lean it back and forth to see that the settlement is gone. also, because of so much agitation the internal bag kind of bothers me. just too fragile for some much shaking (for me). also, the white has TiO2 straight particles. these particles will settle (at least with mimaki) in your head adapter eventually restricting flow. the filter in the head adapter is much more fine than the damper. i'm planning on buying some extremely fine inline filters for that head. so i can no worry so much about pulling a head to change out an adapter. so for now... buy some spare head adapters $15 each from china.
also, setting the machine in white mode i've been told from the firmware makes the machine do more routine cleans (don't know if this is true). but expect it to throw away a lot of ink. my mimaki started from the install set for CMYKlmlcWW. so i can't tell what the difference is.
if you ever clean out a line holding white, clean it out until it is very clean. the white will plaque up on the line and never ever come out. except for as small particles. it can't "melt" in this sediment form. it is unlike printed white with the resin binders.
i bought my 160sp specifically to run white, uv clear, and silver alongside my CMYK i even have water based for rapid prototyping, running to the lm lc head right now so i have four special color channels (you can isolate the lm lc just like the WW by doing a date ribbon swap with WW).
any way i can go on and on with the white ink stuff. i've been printing white one way or another for the last 10 years (even from an old encad 505). maybe roland is easier, maybe i'm doing it wrong. but that's my two cents.
in the next while i'm going to replumb my heads so i can have an automatic cleaning system on the printer. that way i can with a valve switch between cleaning solution or ink right at the head below the damper. i'll send pics when my franken-printer is modified.