I apologize for this being a topic you are undoubtedly tired of hearing given that there is an entire announcement about this, but can I implore you to direct us to a place that would allow people experiencing the problem to download the libraries themselves?
Our server is running 1.12.2. with Pixelmon and CustomNPCs, an unsupported version on this forum but without the means to update even if we wanted to. Nevertheless, we encountered issues with the current 2855 Forge for that version that we don't experience when testing out the same thing with an archived singleplayer client with 2847.
If there is anything we could do on our own initiative to get a server running Forge 2847 it would mean the world. It's understandable that older versions are not a priority and a bannable offense for how excessively it's asked but at the same time there are many in similar situations that simply need to use older versions. Please grant the userbase the means to fix the issue themselves where necessary.