Unfortunately it's not so easy - arm's settings for different weight can change angle slightly - about 3-5 degr (not 30-40 as in video). If you look attentively on pic attached, movement of point 1 doesn't actually affect on angle of frame, which has independent hanging (2) - ( sure we are talking about modern paramotor scheme with moving arms - not fixed as in flattop). Paramotor should be balanced well (my old PAP has excellent balance).
In my video point 1 adjusted in a last (60 kg) position - i'm 90 - as you see effect insignificant.
Moving up point2 several cm can rearrange center of gravity to perfect condition, but it means changing of whole paramotor scheme.