One of the biggest reasons we see so many “why is X not working/finishing/doing what I expect” is because there is no in-game method of explaining to the player what the problem is.
So, the suggestion is, let’s use the same flag UI in use today for things like Looting and Harvesting to indicate that something is Blocked.
If you were to hover or click on the flag, you could be given stock explanations such as, “Hearthlings cannot reach this location.”, or, " The following resources are required, but are unavailable" followed by the display of the corresponding resource icons with quantities shown in the bottom left corner of each.
I believe that this flag alone would help reduce confusion and maybe even cut down on the number of erroneous bug reports. If nothing else, it would also help moderators troubleshoot problems for players, and also help guide TR to the possible source of bugs. Even the absence of this flag, once it exists, would be a diagnostic tool.