If a decision on your application has not yet been made, and if you resign, you will have to inform IRCC even if your eligibility has passed. Also, if you claimed 50 points for arranged offer of employment, that condition will change, there by decreasing your CRS.
Ideally, you can wait until a little longer, stick on. As soon as you receive a COPR, you can resign the same day.
Also, if you have a notice period, then you can resign and by the time your notice period expires, you should have the COPR.