My case was different, I was waited for CSQ for almost years and then gave up and applied for Express entry and got the ITA.. In EE , you do medicals upfront.. While i did my medicals.. I also received my CSQ, so at that point I had to decide if i should go with EE or QSWP.. Consulted my agent, he suggested its better you go QSWP and we can use the same medical results which I did for EE. so thats how i ended up using medicals upfront, anyways they are expired now..
In Ideal situation, medicals should always be done, after receiving the official letter from IRCC.. as it keeps your file flowing.. in my opinion.