What is the logic behind starting with high pressure and then continuing with low? Isn’t that counterproductive? High load in short time is forcing connective tissue to „defend” and produce a toughening response. Benefit of incremental load introduction is discussed in hanging threads and it implies that following such protocol could be beneficial for expansion exercises as well.
2) if you have such a minor difference tunica must be your limiting factor for further BPEL gains. Looks like jumping into stretching exercises (hanging) would be beneficial for both length and girth development in your case