I´m very suppried - and must learn painful - that there is no content channel transcoding in UVC 1.4.3 / MP_1.6.6 !
This means in practice if you are in a multipoint conference with all participants connected with 1mbps and somebody call in with 300kbps the content channel and quality will drop to the lowest common denominator and very poor 80kbps for all participants!!! ;-O
I do a quick crosscheck to UVC 3.0 and this issue seems to be solved. Content encoder quality/bitrate will decrease a little bit but is much better for the other high rated participants.
Please confirm this circumstance.