It was always wise to have your elbow hard against the open canopy just in case rapid braking or EMERG braking sent it crashing forward unrestrained.
I seem to recall that on taxy out most folk were happy to have the seat live with canopy back (although it did surprise me when I first saw it done) as the signal to start was that all pins were removed...and therefore to safe up and rearm was a potential pigz waiting to happen. Best to keep it live and just ‘not eject’ until you’d closed the canopy.
You had to make seat and canopy safe prior to shutdown anyway so I think it was done in the ‘after landers’ and one could therefore taxy around looking ‘cool as’ and wave to the assembled adoring masses.