I’m sure the Grenadier will be OK on the road.
On road performance is going to be subjective to each individual.
After all this is a solid axle machine purpose built for adventure/utility. Yes the g-wagen is driven on pavement, as is the Jeep Wrangler. Do they excel on pavement, not really. This is one of the reasons many previous solid axle vehicles have gone to independent front suspension, and rack & pinion steering. They realized that the customer was spending more time on road that off, and they could give better on road experience by doing so.
Bottom line is don’t expect this to be any better than a solid axle G-wagen on road.