I've carried a BUG in an ankle holster as an LEO for 28 years. Currently, it's a G43 in an Desantis holster. Previously it was a G36 in an Alessi holster, a G27 in an Alessi (same), and initially a Smith Model 37 in a different Alessi.

Quibbling about equipment does not address tactics, and there's a lot of good advice in this thread.

You'll have to practice to access an ankle gun. That does not include going for it during a "High Noon" fictional shootout (aka neckbeard fantasy). It does include a good "getting off of the X" response to a threat and getting to a place where you can fight in the most unfair manner possible.

Important safety tip, if you're going to practice drawing with an ankle gun, you need good knee pads and to be able to take the holster off to re-holster the weapon after each drill.

Having taught concealed carry, there's nothing wrong with a BUG tool in a well trained and practiced survival toolbox.

If you've got access to a quality trainer who teaches sound tactics, I'd invest in training.