woodpeck, You are right, at this border section you would not see any signs prohibiting crossing the border, and you would see many people crossing this border.
Mazda05 uses a substitution of concepts, explaining its actions.
The legality of crossing a particular section of the border is determined by the relevant authorities, but is not a reason for restricting routing. When constructing a route in a foreign country, the OSRM does not require a valid visa or other document to construct the route.

Dear woodpecker.
This site has no restrictions, because it is not controlled by Ukraine and is not subject to their laws. I personally have passed there many times and have not seen any obstacles to this

В очко засунь своё рішення КМУ