How about just adding the following setting in Preferences:
Culling Distance: Default 30m - Settable all the way up to your current render distance
This will allow builders to NOT cull objects within a settable distance, not matter if they are hidden or not. Distance would be from Avatar (just like the current camera limitation).
The current mechanism (debug menu and turning it off, or obscure key combo) does not save between sessions, and it may be too obscure to find for non-forum-goers.