No longer being able to search for any installed plugin via Quick Actions is a really big workflow breaker 
If for some reason not having all plugins show up in Quick Actions was considered a better approach (e.g. to focus Quick Actions around Figma’s native tools, for performance improvements, or you’re just trying to change the user behaviour towards running plugins without installing them) even though using plugins now became a chore, can you please, at least, create dedicated keyboard shortcuts to open each tab in the new Resources Panel?
Shift + I could be reverted to open the Components tab in the Resources panel
Then just add two more shortcuts, one for the Plugins tab, the other for the Widgets tab.
With these shortcuts the user can search for a specific type of resources and run/place a resource completely via keyboard (at least once you also give access to each plugin submenu options directly from the panel via keyboard).
It would just be better to have Quick Actions looking for everything since it allows to look within each plugin submenu options but it’s having these shortcuts its the bare minimum to make plugins a little bit easier to reach again.