It is possible to have different place for "Workflow Integration Plugins" folder instead of "C:\ProgramData\Blackmagic Design\DaVinci Resolve\Support\Workflow Integration Plugins" location?
The BMD_RESOLVE_SUPPORT_DIR environment variable does not work for "Workflow Integration Plugins". As far I undertand it works partially for "Support" directory.
I don't think there is, but nothing prevents you from installing your application wherever you want and executing it from another application which is in the official path that Resolve enumerates.