Just quick example of something I’ve been using.
I have a number of optional items that I only want my regression to do sometimes, to simulate real-world examples of not filling in every field. Here is how I weight it to only perform the action 1 out of 10 times.
if random(1,10) = 1
put "do it"
else
put "don't do it"
end if
Of course, you can weight it however you want by changing the 10.
You could also write an external handler to return a T or F based on the passed weighting.
I hope this helps someone.