I've just tried upgrading my setup to run python 3; my conclusion is that the oak-d is a no go on ROS 1 / Raspberry pi3.
I'd love it if someone ould prove me wrong; but here's how i got there.
As Python 3 is necessary i found this tutorial explaining how to configure ROS 1 to run Python 3 instead of default Python 2
(apologies if there's a no-link policy i missed, can be removed in this case!)
But the page is about ROS Melodic, which is based on Ubuntu 18.
When trying to follow the indicated steps nontheless i met several pip syntax errors which when googled point to compatibility issues that could involve the Python 3.5 version i use
Python 3.6 is not available anymore for my environment in any directory i've tried
Moving to Ubuntu 18 is not an option on my Pi 3 (already tried, so slow it's not usuable), so for me it's a no go in my current state.
This may rush switching to Raspberry pi 4 when/if they get back to regular prices so i can use the Oak-D in my project !