With hanging, the only things that likely affect gains are:
(1) How many total minutes you’re hanging each time you hang (the summed time of your sets, that is)
(2) How much force (weight) you’re using each time you hang
(3) The angles you’re hanging at
(4) The frequency with which you’re hanging
Varying any of those four factors is a possible avenue to renewed gains. There is no “scientific” evidence about the relative importance of these factors. Conventional PE wisdom says that factor (1) is most important, so long as you’re using a sufficient weight (2) with decent frequency (4).