A couple of fairly recent historical cases to be familiar with regarding a request for release from mediation.

Last year, on June 10, 2022, the bloc of twelve railroad unions were released from mediation one week after requesting a proffer of arbitration. Ten of the twelve unions had filed for mediation in Feb 2022. When they were released from mediation, they'd only been in mediation for 136 days. That may be a record short time for a stay in mediation from entering mediation to a proffer of arbitration.

Two of the twelve unions had filed for mediation several months earlier than the other ten. On Feb 23, 2022, those two unions (BMWED and SMART-MD) requested a release from mediation. They were not released until all twelve unions were released in June 2022. The letter BMWED and SMART-MD sent to the NMB was very short and general in nature.

In 2018, the Frontier pilots requested a release from mediation. They were not released. I am not sure if the NMB simply did not respond to them or outright denied their request. Maybe someone who is familiar can fill in the details. I have seen Frontier's request for release. It was very long and full of details asserting many of the same sorts of arguments SWAPA is making. I cannot find a copy of it now but it seemed pretty convincing to me. However, the NMB was not swayed (but we have a very different NMB today).