I am curious - when I do my ESP32 projects, I often set up "start up Wifi AP when not configured that shows config page". This allows easy configuration via phone, and does not require any custom app development. The only downside is the requirement for the physical "setup" button (in case of bad wifi or something), but I don't think this would be a problem for your device?
Any reason to prefer bluetooth over local web server?
I did this for my original project [1] but I wanted something simple for the end user. Having to explain a user to visit a specific IP on their device which may not work because of what ever routing issue is not something I wanted to have to deal with. The app does add a dependacy but all Bluetooth characteristics are public and documented [2] so you can use any Bluetooth app to configure the device.
[1] https://sschueller.github.io/posts/vbz-fahrgastinformation/
[2] https://github.com/TechdroidInc/stationdisplay/blob/main/BLE...