That example with Lawton S68 is spot on and if Lawton did not commit 100% to the run, would have been stopped, maybe an error, but ran that unders line "right through"....Croker of all ppl scored similar vs Bris when we spanked them by 50 in 2021....hard unders lines with purpose.
It's a good habit to get into, as it completely bends up and kinks the defensive line allowing space as the defenders are forced to commit and if they don't - your on your way.
Funny how all these bodies in motion when winning well, yet behind or struggling there are NO runners....Manly recently lack those hard nosed ball runners, who want to bang down the walls and Paseka , Oka, Tuilagi types will be far more dangerous running with pace and power than that flat footed catch and run stuff, plus team mates will love taking the next run after they have scattered the defenders and got the defence on the back foot !!