I took it apon myself to time the ammount of time Luigi/P2 was moving and here is what I got. (By the way, this is an approximation of movement time)
Luigi’s total movement time on ground, not in the bubble.
(I’m only counting Horizontal movement for timing, no vertical movement)
(DISCLAMER This is an APPROXIMATE TIME I did not time cutscene movement and OverWorld movement seeing as in both of these Luigi/P2 has no control of his movement)
At 6:02 in the run Luigi moves for 4.09 Seconds in World 5-Pirannah Plant
At 10:06 in the run Luigi moves for 4.26 seconds in World 5-4
At 10:55 in the run Luigi moves for 0.49 seconds in World 5-4
At 15:49 in the run Luigi moves for 1.85 seconds at World 8-2
At 19:25 in the run Luigi moves for 1.60 seconds in World 8-Airship
At 20:09 in the run Luigi moves for 0.96 seconds in World 8-Airship
At 23:46 in the run Luigi moves for 1.73 seconds in the final boss level (This is tricky to time cause Luigi is off screen for a bit and then comes back)
Out of a 26 minute 35 second run Luigi moves for about 13.13 seconds.
I don’t know if this helps but I thought I would put this here.