Interesting frame. This is the most road like geometry i've seen with 45mm tire clearance. Trails is short at 53mm so its gonna be fairly lively for a gravelbike. Won't work that well on the very technical stuff but it'll probably feel quite nice on the longer stretches of plain gravel.
Cables are quite funny... External cables for rear brake and derailleurs but front brake has to go through the headset! Look closely at the pictures...
I'd say you have to go fully internal and live with the cable ports on the downtube.