My other older theme (Asteroid) has this snippet included on the functions.php. I’ll add it to Frontier on a future update, maybe version 1.0.9
Frontier 1.0.8 was already submitted and is just waiting to go live.
Note: version 1.0.7, the one you’re using right now, adds an additional 10px to the entire width. Consequently, your logo does not span the entire header anymore. You may want to subtract 10 from the “Content Width” value on the Options to get it back to normal.