HI there,
I think that'll all depend on your own personal risk tolerance. That being said, I would consider my position from the ESP as part of my overall portfolio. So as an example, if PKI makes up 40% of my portfolio, I likely would not add. But if it only makes up 5% - then yeah, I certainly could. Then again, if I am regular making contributions that 5% is likely to grow over time.
Bottom line, it'll come down to what kind of PKI allocation are you comfortable with. In all honesty, I'd likely not add and just positions elsewhere simply because I know my PKI position is regularly being added too.
Mat