Mandatory but..."The Existing Shareholder Exemption limits a shareholder to a maximum investment of $15,000 in a 12-month period unless the shareholder has obtained advice regarding the suitability of the investment and, if the shareholder is a resident in a jurisdiction of Canada, that advice has been obtained from a person that is registered as an investment dealer in jurisdiction."
In other words, you can't buy another $15,000 of this PP unless you've been duly warned. If you are asking, then my guess is that you won't heed any professional advice anyway.