Especially point 2 and 3 are really important (in my opinion). I'm not sure what exactly you are doing, but this seems to be quite a hack - and should be fixed in the offending mods or in forge/netty directly.
There is probably a reason why there is a limit to the packet size and you dont talk about possible issues that may occur when using this core mod.
This mod already cover Coremod's policy : it is signed since version 1.1, and contains nothing but the Transformer class and some glue to update its description with details of modified classes. BTW, version check is done via Forge's update checker.
As documenting the way it works, everything is in the logs, really. The names and details of the up to two patched methods, each with up to two modified constants are clearly reported. No "hacky" interception or bypass...
I used the lightest (and safest) way, expecting users feedback showing it was enough to do the job.
But, IMHO, this constraint shouldn't be enforced on the client side... You ever trust the server or don't play on it.
This side restriction might be done in future Forge release, leaving existing ones at bay.
As of what may occur using this mod, it mightjust works and having users not crashing.
It doesn't impact data, you can even add it to your setup long enough to reconnect and move away from offending chunk before removing it, if so you wish.
Still hoping feedback from users of the mod, in order to see if I should go any further here, my own mod saved me the day couple times already, and that's already enough.