To add one additional point of why not to do this. As a hiring manager it could potentially highlight that you are seeking the wrong things and will jump ship

To add one additional point of why not to do this. As a hiring manager it could potentially highlight that you are seeking the wrong things and will jump ship at the first sign of a better offer. And if there was indication (by dates or other means) that you used it to gain a higher counter offer from an existing employer it would likely leave a negative impression. Every employer (especially in tech) knows this stuff happens, but highlighting it and "bragging" about it is not favorable. There is a way to use the information though, when discussing with an employer about what your salary requirements are, you can state well, I had an offer from XYZ for 123 recently. And then explain why it just didn't meet your needs, e.g. you learned at the interview it wasn't a good fit or whatever. Just be humble about it and that will go a long way. This also lets you kind of answer a question without really answering it. e.g. make them put a number on you.