With OBS Studio 28.0 comes another restriction: Per-User Plugins. This is currently only enforced on ARM64, but may soon be enforced on all architectures. Adjusting the Packages installer to generate the correct files is relatively easy.
Unfortunately the MacOS Package Installer has some problems figuring out if it should show the user the correct step or not, and may even ignore our settings entirely. This bug has been first reported in 2010, and has since then been re-reported in 2016, 2017, 2018, 2019, and 2020 where it was finally turned into a community wiki on StackOverflow.
With OBS Studio 28.0.0 a new requirement was added to MacOS plugin: Loadable Bundles. These bundles are similar to Application Bundles, and have many of the same features, but are designed to be loaded by Applications instead of being the Application. This allows for almost all of the advantages to persist, with some minimal drawbacks.