Yeah they will. Mine has a double chainset. Email them if you want it. It's a much more versatile bike with the extra spread of gears.
Just to update you as I did email Planet X and they replied, "
A 2x system is possible on the Tempest but at the moment we do not have stock for a gravel-specific double chainring on the front.
We have road style double chainrings but you may find yourself over-geared for the type of riding that the bike is intended for. "
It's certainly not a deal-breaker for me as i have been riding with a 1X system for a while now.