Is it possible to apply for an education visa, and after that for an Elite visa? I have read that this might be difficult to obtain and wondering if that is true and also why? Tnx folks

Is it possible to switch directly from Education visa to a teaching visa? The employer is recommending cancelling the ED visa first then apply for a COVID visa then change over to a teaching visa. But she also said that for the covid visa, the stamp given is usually 15 days first then after 15 days, need to go back to the immigration and see if they will stamp the additional 45 days. My other question is, does the immigration usually approve the additional 45 days?