Can we use the beta of copter 4.1?

For a cube orange, the beta of copter 4.1 is available: ArduPilot firmware : /Copter/beta/CubeOrange

Do you recommend us to use it or is it too soon?
Do you know when it will be a stable version on Arudpilot and Cube Orange?

Beta means it is not enough proven to be stable. So use it as your own risk.
If you want to try new features or do some testing, just go for it.

It becomes stable when there is long enough flight hours proving its safety. Ardupilot dev will announce this when the new stable is ready.