abs shrinks like a swine.
So if you keep the model at a constant temperature it all shrinks together rather then a little at a time. Stops warping, cracking and not sticking to the print bed.

Yes you can print abs in an open printer - but it's not easy.

Also you will find that pla is better than abs for most purposes.
And for those other things pet-g is better than abs.

Abs is cheap - but for me that doesn't outweigh all it's negative points and pet-g is getting cheaper all the time.

The quidi is probably your best bet if you want dual extrusion and insist on using abs :-)