Oh understood Russell Blake but think it should be fine if they told you to come back for stamp...meaning it must already be approved. They are holding your passport or do you have it?
You could apply for Non O in Thailand instead then no insurance requirements (outside of any Covid coverage that may required if Thai Pass still required at your time if travel).
Going through the process and some things to watch for as far as moving $$$ from Canada ...and a few other differences been applying in Canada and in Thailand