The Rendu series has always supported pause frames. Historically, customers have needed extra help with network setup if they used managed switches. The need to enable flow control in the managed switches is required to get things to work properly together. These managed switches as discussed sometimes have their flow control disabled so the request is ignored.
Now move forward to the introduction of the opticalModule. Two customs have reported issues with HQ Player / NAA while using an opticalModule and micro/ultraRendu combination. One customer moved to an opticalRendu which has a built-in switch which inherently doesn't have flow control issues. The other customer reports no flow control issues when he excludes the opticalModule from the network. As a result, we added some additional code to Sonic Orbiter to request pause frames when using an opticalModule and John confirmed that this worked in the lab. This fix was then uploaded to all the Rendu software and all is great. Except that this fix still doesn't work for the one customer. We don't know why the fix doesn't work for the customer but we will have an alternative for him to try soon.
Jussi feels singled out here, but that is not the intent. We are simply trying to help a customer with an issue, fix anything that is needed, and move.
Finally, I think you are out of line in the way you spoke to John above. You are not part of the design team, you don't know what is going on behind the scene, and you don't have all the information to accuse him of wrongdoing.