Maybe worth noting that the migration tool does support migration of apps now... but only from one version of Studio to another on the same PC.  I think when we do the proper appstore integration into Studio then this will solve the problem you mention of migration.

The idea of installing more than one plugin at a time is a separate one and maybe a useful feature for admins guys setting up machines so they have the same configuration with a lit of approved apps.  I think relatively simple to do now with simple scripting, but perhaps worth a small utility for it  on the appstore.