I think there is precedent e.g. eure routes in the UK. So, why not...
I think that AH140 and AH142 look good.
I'm not sure about AH141's east end. Does the concurrency with E8 really end at exit 830, not at exit 833? The pdf indicates a length of 272km. The route via exit 830 has a length of 277km, the length via exit 833 is 289km. The route on "primary" is indicated being 265km long but the length to exit 830 is only 856km. To 833 279km. The route on "Class I" is indicated being 7km but it's 18km from exit 830, 9km from exit 833. I'm not sure if it's 100% correct but I'd say it's good enough
to the best of our knowledge.
https://travelmapping.net/ When a highway system is deemed correct and complete to the best of our knowledge, it becomes "active"
I don't think that we will ever get evidence due to non-existing signposting. I'd keep it as-is, add a note to a readme file on github, and close the issue.