Si je me trouvais à ta place, j’aurais pas envie de me la mettre à dos.
There's nothing odd about using this sentence construction, as long as it is some other person than yourself that you say you shouldn't make an enemy of.
On the other hand, when you use the hypothetical expression "à ta place", it is quite possible that you end up saying something like the following as a threatening remark:
Si je me trouvais à ta place, j’aurais pas envie de me me mettre à dos.
{with the meaning of}: Tu n'as pas intérêt à te me mettre à dos.
With the hypothetical expression "à ta place", "je" is the subject by default, so the 1st "me" is required as the reflexive pronoun. And then, it is also the 2nd "me" that I wouldn't want to get on the wrong side of. So you're stuck with two mutually exclusive "me"s conflicting with each other.
How do you work round this awkward phrasing?