Hi,
You can spray MM Acryl undiluted with some ABs. I've done so with my Iwata Revolution CR (0.5 mm nozzle) but I'd recommend thinning it, especially for any smaller nozzle. If you want to do fine lines up close at low pressure you'll need to thin it, 50/50 or more. As Montague says, 'light coats, build it up".
For color change cleaning, I do similar to Montague but, using gravity feed AB's I do it a little different:
After first color,
1. Empty first color and put Windex in the cup
2. Spray until no solid color (only Windex is spraying)
3, Dump remainder of Windex
4. Wipe inside of cup with tissue or paper towel
5. More Windex in cup, spray a few seconds and dump
6. Change to new color and spray, first on scrap then model