Degradation preferences and limiting the probation process


I’d like to modify degradaton preferences in my JS client. Can’t find any support for this in mediasoup v3 client API. Now the client keeps too low FPS while the resolution is HD. I tried to call WebRTC API methods to modify degradation preferences using Peer Connection retreived from producer after produce() is called, but can’t see any difference in the behaviour.

Another question. Probation channel tries to fill all the bandwidth to calculate its width. But I’d like to set some upper limit for it to minimize negative affection to other running network applications. If I know that 2000 kbps is enough for the client, I don’t need to fill the channel more than 2000 by the probator.
Is it possible? If I change offer remote description in mediasoup client library, adding b=AS:2000, would it affect the probator?