If you're using ISBoxer, you can set up multi-step keys that will delay for a pre-set amount of time on each step, meaning you can get as close as it's possible to get to a "priority" rotation. I haven't tried nested multi-step keymaps but that should lend even more flexibility to things. It seems to work pretty well for my monks, which also operate on energy and procs. Of course, I haven't made 60 yet so I can't give you any hard numbers for how well it works.