I tried stand development a few times, and never succeeded, usually got horrible over-development. *For me*, it didn't work at varying temperatures and only one or no agitation.
I went back to basics, and now use original Orwo R09 at 1+40. In my Paterson tank, I use 350ml of solution (8.75 ml of concentrate). Original R09 is about 20% less concentrated than Rodinal, so that equates to 7ml of Rodinal in my tank.
I use more solution than the minimum, and my negatives are far, far better, and more important, are now of consistant quality.