Can I copy procedures from one project to another?
Is it just a matter of moving the files over?
I tried duplicating procedures in that way but that didn’t work.
Yes, you can copy the files, but any dependents must be included. This is hard to verify other than it breaking when you try to start the plugin. You must also make sure the .procedit file that goes with each .proc file comes along for the ride. All procedures are referenced by (internal) ID and the name/location is fairly irrelevant. Also, you can’t do any of this whilst the plugin is running, they are only scanned for at plugin start-up.
Future support for this will come when I look at procedure libraries and the management of things like that.