Based on what I see at http://plugins.roundcube.net/, and my experience with Composer, it seems like all plugins should have their own repository, and should be installed either with Composer or they can be handled via git submodules.
Is there any particular reason the default set of included (but not activated) plugins has not been separated out from the main repository into repositories of their own? I would even argue that skins, aside from the default, should be separate repositories. My group manages our installation with git and it would make my life a ton easier if this were the case.
I saw an answer to "[RCD] update.sh clobbering custom plugin configs in main.inc.php?" earlier today, suggesting that a config file within the plugin should be edited. Plugins are basically vendor code, wouldn't it make more sense to make a plugin_name.inc.php within /config, and have a plugin standard (in the form of a config grabber method) that grabs the appropriate config file? This way, the plugin could be updated by composer or git, and there'd be no worry about overwriting configs, or editing vendor code. It'd encourage plugin writers to keep their config separate from the roundcube config, because there'd be an easily accessible function for it.
Quite happy to write/implement this myself, so long as the idea/direction is acceptable to the lead RC devs.
Thoughts?