LMIA exempt work permit extension -chances

[Lady_Ashka]

I will be applying for a WP extension, the same employer, University Professor (Post-doc). I have all the documents required (passport, IMM5802 from my employer, photo, proof i meet the requirements, employer payment receipt, invitation letter, employer questionnaire, and I am inquiring about the itinerary in a different post). I will pay the fee, apply online. I will also attach a police clearance, and am wondering if I should get an upfront medical exam, or wait until they tell me to do one (my job does not require it, I am an academic working at U of T)

Are there any chances that the application may be rejected? Is there something else I should know/remember about?

My current permit expires on 30th of September, so I am giving myself more time than normally... What are you thoughts?