How do you mean turn off or freeze? Are you doing this by turning off or freezing the layer the corridor is on? If so, turning it off doesn't actually change the speed of things because items on layers that are turned off are still regenerated, just not visible. Freezing the layer would affect this better.
But I'm also wondering about how this would affect another user? If you're in a file, using your storm example, and have a reference to the corridor, then the storm designer can manipulate the display of the corridor as they see fit for their design. Unless you're also in that file making changes when they're not, there wouldn't be an issue. If you're in the corridor and making changes, that would affect the storm designer who needs to synchronize your changes. Turning layers on and off in the corridor file won't affect them, only changes to the actual object.
But back to your original question of best practice:
Data shortcut anything you need the DATA for. If you're in the storm file and you need to see the corridor subassembly sections in your design profile, then data reference it in. If you're only concerned about the top of the grading and have a default minimum depth from there, then you don't need the corridor, you just need the surface and you can generate a 'minimum cover' surface, using your design surface and an elevation drop. These would be added to the profile to design against.
If you don't need the data for an object, an xref will suffice. Especially since you can label through an xref, this will let you extract some data without having to have it directly in your file too.
Adam ReillyCivil 3D 2026 Creator A16 AI+ A3HVFG Windows 11 Pro AMD Ryzen AI 9 365 w/ Radeon 880M LinkedIn |  Austin CADD User Group LinkedIn | Discord |  |