Running Lua code during demo playback

During normal gameplay I am able to use command lua_run to run server-side Lua code and lua_run_cl for client Lua code (of course if sv_allowscslua is 1).

But during demo playback both of these commands seem to be ignored. Even simple lua_run_cl print(“Test”) does not actually print anything to console.
I am wondering if this is even meaningful to run clientside Lua code during demo playback - will it work or not? What is the correct way of doing it?

Why would you want to?

I have one specific goal - to hide player name and health during demo playback. I have another whole thread about this: http://forum.facepunch.com/showthread.php?t=1536798 but it kinda died.

Some of the posts suggest using Lua hooks, but I can’t figure out how to even execute Lua code during demo playback.

In general, it probably may be useful if you want to modify behavior of addons during playback, but I am interesting only in one particular case now.

clientside rendering and scaling of models, for one thing (wiremod holograms for example)