Pumps for road bikes are designed for HP/LV. Mountain bike pumps are more focused on HV/LP and now fatbike pumps such as the Lezyne Micro Floor Digital XL which I have and carry bikepacking on my fatbike are even more about volume. Now that could possibly be used to blow up a mat, but mind you, I wouldn't bother using as I use the stuff sack method along the lines you mentioned.