Dynamic Brush creation current cycle number

Hi All,

I'm pretty sure the answer is I can't do this but thought I'd ask just in case I missed something.

I need to be able to pass a Random Seed per cycle i.e. if the cycle is set at 1-20 i have 1 random seed per cycle.  or some way to persist a count between stamps that I can manage myself.

What I'm trying to achieve is passing the same dynamic alpha to the brush for the duration of the cycle so say 20 stamps then getting the next one. 

From what I can see this is not possible, no way to persist any sort of state between stamps and the only other options are as below, have I missed anything ?

When creating dynamic brushes for substance painter the exposed variables in the documentation are

stampCycleCount   total count

stampIndex  iterates through cycle count resets to 0 each cycle

$time in seconds but can't get brush velocity to do anything clever with that as a workaround

In painter from a random seed point of view you can have single, random per stroke, random per stamp.