A friend told me about two relatively new jazz standard backing track apps that might be of interest. Both feature professional jazz musicians (not samples) in a quartet setting and playing the standards. You can change key, tempo, etc. And they sound great. Way better the iREal Pro. Cost is reasonable considering the quality of the musicians and songs.
-Quartet: https://www.quartetapp.com/ Currently there are 6 packets totalling over 600 songs, which you can purchase separately or as a bundle.
-The Feel Book: https://www.thefeelbook.net/ They use a subscription model. Not as many songs, but they keep adding.
There are lots of reviews on Youtube.
After checking out some of the example I decided to get both. Easier to use than BIAB.