Post Office might have moved to somewhere else in this vicinity, since this exact location is clearly residential.

https://osm.mathmos.net/postoffice/progress/CF/#18/51.51343/-3.15340
https://www.postoffice.co.uk/branch-finder/5676118/llanedeyrn

What's the difference between these 3 relations? Can any of them be merged?

relation/11993157 - "Test Way Cycle route" route=bicycle

relation/9061 - "Test Way" - route=hiking

relation/6565505 - "Test Way" - route=horse

Wikipedia also has 2 articles, but it's not clear why the bicycle route is much shorter.

https://en.wikipedia.org/wiki/Testway
https://en.wikipedia.org/wiki/Test_Way

Is there a reason why there's 2 different relations for Wirral Way?

relation/307872
relation/18279331

Is "Roach Valley Walk" instead "Roach Valley Way"? Also there's a gap in the relation here, seemingly due to more detail being added to the path/road intersection.

relation/7974115

https://en.wikipedia.org/wiki/Roach_Valley_Way

Does this road have a name?

way/673630071

Does this road have a name?

way/35548647 (smaller road ways either side of link as well)

construction key is for specifying ongoing construction not for whatever construction=1865 is referring to way/990977037

There's various other tags that can be used:

construction_date=*
year_of_construction=*
start_date=*
opening_date=*

Can a relation be created for both "Wetherby Railway Path" & "Harland Way"? Is one the name of the path and the other a signed route?

Is Thanet Coastal Path longer than this short way? If so can a relation be created, ideally with more of the route included?

way/94430863

https://www.wikidata.org/wiki/Q133838271