Could I have a plugin that allows players that use MCPE 1.0.4 to join 1.0.3 servers? I am sure that this plugin exists because I have seen it in a server. If this is advertisement, sorry
Those servers are using a fork/spoon of PocketMine: Elywing. Elywing is foolish enough to accept multiple versions in one server. Mojang bumps the protocol for a reason. There are things that can break if two different versions play in a server.
I'm currently working on a new network structure to allow cleanly supporting multiple protocol versions simultaneously, but ran into design issues. I can tell you that hacking protocol numbers in is not going to work well, you're more likely to crash your players than get it to actually work. And if it does work, there will be things that won't work, such as transfer.
I also use Elywing for 1.0.3. If you see better in the plugins of the server, you will see a plugin named MultiProtocol
Ok. Are you working this on Elywing too? Is there any plugin that allow that? As I can see the server it told supports 1.0.3 and 1.0.4 each and it uses Elywing
But there's a fine line between warning someone not to play with fire and straight up blocking the access to the fire