As a Roblox developer, we have since the dawn of Roblox used hinges to easily mark surfaces.
Source: Finale of Part Surface Changes: No More Hinges
[First of all, I hesitated on making a feature request in the first place because I saw the key words “we plan to further solve this problem with the new Lua Dragger/Move tools.” Thank you for recognizing this is a problem and not simply going to go away just because the old surfaces are going away.]
Personally I have never had any issue with slapping a hinge to visualize faces. I compare this to when developers used to have to use game.Lighting for storage of models that would not be used in the game until later. Of course we shouldn’t be doing that, but Roblox didn’t provide any better alternative until ReplicatedStorage.
Both of these examples are user experience vs intended design.
Developers gravitated to using hinges to visualize part face due to it’s simplicity and ease of removing once we no longer needed it (Or even just making the transparency of the part 1)
Developers did not use the alternatives Roblox now recommends because it was not faster to do, therefore, not the user experience dirt path in the above picture.
Attachments:
My verdict is there is nothing in the properties of the attachment that display face direction which means I can’t tie the orange, yellow, and red arrows to part face without first knowing the face I put the attachment on. This ruins the point in my opinion.
Adornments:
My verdict is after inserting the default adornments I still am left with a lot of work to do so it is not a viable replacement.
Decals:
My verdict is these work the best. Having a property called Face on the object itself makes all the difference. Again though, this is no different from the non elegant solution of hinges.
If this is solved, developers will have less nuance in something that should be simple and easy to visualize.
This feature request is to provide an elegant solution to the developer pain points marked above to solve the easy visualization of geometry faces.