thinking about it, pressure may not be the best way of looking at the issue, since pressure is defined as force per unit area, so you'd have to measure any changes in the surface area of the lip as well as the force applied as well as the compressibility of the lips.
It'd be possible to glue a strain gauge to the reed, but calibrating it to give accurate measurements of force would be a hard job..
The amount of force applied would depend on the strength of the reed and the tip opening of the mouthpiece. The bending of the reed may not be lineararly proportional to the force applied.
the advice given in Harvey Pittel's video is just that - advice - it's not a set of hard and fast rules, just a few things that you might like to take into consideration or not. Some advice can be helpful, or it can be not relevant to your particular circumstances. As with learning to talk or ride a bike, the learning comes from the learner, not the teacher and a good deal of trial and error is often involved.
There are many different variables under our control when we play a musical instrument, but trying to be consciously in control of them all is no more possible than consciously trying to control your vocal cords and larynx when you speak or sing.
I'm in agreement with Altissimo
now I'm getting worried...