I like the scaffolding you’ve added Greg, unique take on the idea what with climbing up through the middle. One issue though is finding the ladder when you are above. How about a hatch overlay on walkways over a ladder. Something like this: 
I’ve also created a walkway pattern akin to steel diamond plate: 
Issue with that is, you cant use the Scaffolds as Floor then since every single one would have a Hatch ontop of it.
I assumed this was the case, though technically if there was a ladder beneath then you would be able to descend so having a hatch would make sense, even though it would appear in many places.
I don’t expect it to appear above catwalk bridges though, I know it can differentiate between them because the model changes to that nice beam shaped block beneath. regardless it’s an interesting take on the standard scaffold design and looks a lot better for access.