Lezyne makes two compact pump types, high pressure (HP) and high volume (HV). HP is for road bikes with skinny tires. Use HV for a packable fat tire pump. In the garage, I use a compressor. On the bike I carry a Lezyne Alloy Drive HV pump. There's an article on BikeRumor about it.
Yes, the Micro Floor Drive XL is the fat tire pump because it only goes to 35 pounds. The Alloy, and all of the other HV hand pumps, go to 90 lbs. I'm not sure why anyone would buy the XL as the Micro Floor Drive HV is the same length and style but pumps to 90. I find Lezyne's vast array of pumps confusing, overlapping, and poorly differentiated—but all are quality products. They are a pleasure to own and use.