Good to hear 
If I’m remembering correctly, the latest Companion Software images should have Python 2.7 and 3.4 available by default. If you’re wanting to install a more recent Python version there are some instructions here. That said, adapting existing services/programs to successfully use a different Python version may not be trivial, especially if they were written without Python 3 compatibility in mind.
The Companion Software supports Raspberry Pi 3B hardware, yes - I wasn’t even aware there had been earlier hardware versions supported previously.
If it’s relevant, BlueOS is supported on Raspberry Pi 3B, 3B+, and 4B, and the base operating system for the images we build is Raspberry Pi OS Bullseye, which comes with Python 3.9 by default. The BlueOS-core docker image (which most of the services run in) also currently uses Python 3.9, although that may be upgraded soon.