I got married 10 days after receiving my ITA. My spouse is a permanent resident of Canada already. Now, I have all my documents ready (including my marriage certificate and my spouse's PR card), should I mention this in additional letter of explanation. The only concern I have is that will the processing time increase because of this? and is there a chance of my application getting refused though my points remain unchanged after change in marital status.
Cogratulations.
Since your spouse is already a Canadian PR, the processing time will not increase in your case. You must mention about this change in LOE and submit all the required documents in your e-APR.