I am interested in BT 5.0 for the better range. But I'd be happy with 4.x for basic BLE.

Here's a little about my project:
I'm developing a lighting controller device with a HTML5/JS UI. The device will be on a private network and will not have internet access. The primary communication will be Ethernet/WiFi (to an industrial panel computer or tablet), but a future feature will be control via BLE.
For the future feature, I'll compile an almost identical HTML UI into a Android+iOS app using EvoThings to enable the device to be controlled via BLE.

So is there an inexpensive (~$2) add-on to the Omega2 which would enable BLE? I feel like using USB will add unnecessary cost. I would prefer to solder on a SMT module.
Also, would a SPI, UART, etc. connected module be supported by the kernel, or does it require custom drivers/software?

How will the Omega communicate to the BT LE module/chip? USB or something lower-level?

I'm considering the Omega2 vs. ESP32 for a project and it may come down to built-in BLE support that the ESP32 has. The Omega2 currently requires a USB add-on for BLE and that's adding too much cost.
Thanks.