I don’t have first-hand knowledge of OPEN bikes, but I’ve known several riders who have them, and they are more prevalent than any other single bike I’ve seen in the Michigan gravel race scene. Everyone I’ve ever spoken to about them loves theirs.
When I am in the market for a new gravel bike, they are right near the top of a very short list of what I’d consider buying.
If the geometry works for you, I wouldn’t hesitate at all to use it as a road bike.
My 2c. Good luck🤘