This is just an idea, which might work for some people.
Even though I've now been bowling this stuff for 7 years I'm still learning all the time and I'm still trying to figure out ways to improve. My action seems to change from one season to another, although this season I felt a lot more relaxed and I tried not to tweak what I was doing at the end of the season last year and it does seem to have worked.
There's a few things I know I can do to make small adjustments to my bowling that make a significant difference. One of these is to consciously get right up on my toes when I'm pivoting. Because I don't do it to the extent that perhaps I should, when I do so, it does increase the risk of my bowling being slightly more wayward, but it is recognisably effective in that it spins far more, turns off the wicket far better and often with more bounce.
The conclusion therefore is...
(1). A small adjustment in what you do with your foot e.g. get up onto your toes may make a significant difference to what the ball does at the business end. What you are doing, when you do this (potentially) is bracing your leg in your pivot, this also gives you marginally more height.
(2). Conversely, if you're someone who bowls leg breaks in a way that is very consistent and you feel that you want to vary it in some way, you could possibly try the opposite - reduce the rise up on to the toes to produce a ball that spins less? I know this goes against the grain in terms of what you're told about the pivot, but it may work for you and might be worth looking at as a subtle variation?