The above simply changes between position size of 3 or 1 depending upon if you are above or below 10k. Is this what you mean as your description is not very clear?
This version multiplies position size by 3 every time a new 10k profit is reached and divides it by 3 every time 10k is lost down to a minimum size of 1.
Not tested.
EDIT:2019/09/04. MIN in line 11 should have been MAX – I have edited the post to correct this.