I would say it depends. Even if you would like a residency in a place in a competitive fields as mentioned above- it does not mean the professor you sign up for at Mayo or Yale will have any kind of pull, especially if it's just an elective. It would be an online class I am guessing- so how much time is this professor actually going to interact with you and speak with you to speak on your character if the end goal is to obtain a residency? My suggestion would be to do some research on the professors teaching the elective first to see what the situation is on them..
If youre interested in getting a competitive residency network with the people directly in charge. Go to conferences, reach out through email about literature published, create a direct conversation... I am all about minimizing the crushing debt one accrues after med school if at all possible.