I'm also writing a feature request for this, but in the meantime, your process isn't working for me.
Ctrl-Shift-F does nothing. Neither does Cmd-Shift-F.
In the nested sequence, when I hit F, it opens the frame in the multicam sequence in the source viewer. Hitting F again does nothing. So how do I get to the original clip? I'm using Premiere 6.0.2 on a mac.