I'll offer a contrarian opinion.
I think if there is no feasible danger of contacting the energized live parts on top (i.e. not pulling new wire into switch) the line shield should serve as an effective barrier to contact. That is it's function. It does not have to be made to resist blast, as it prevents blast from occuring by prevention. At some point, some allowance must be made for practicality; there is a point where safety is not increased significantly but added work goes thru the roof.
Let me hasten to add that if it is not a big problem to de-energize switch first, I'd do it, and ya still gotta make sure the load side is actually dead.
