I have to admit to being a little intimidated by these changes, probably due to me being a rank amateur not a proper developer. I am going to take you at your word that the changes are backward compatible and that anyone using my plugin as-is will still be able to use it after v7.53 is released. I have no extra features currently planned.
Nevertheless, I am going to slowly try to get to grips with the changes which would need to be made to my very simple plugin. As a start I tried to download the sample from the manual but am getting
You don't have permission to access /downloads/interface_demo_plugin.zip on this server.
so I'm not off to a very good start.