If this doesn't yield enough tree shaking/size-reduction here are the options we might consider for Microsoft Graph:

setup a mono-repo (lerna)
main project is the models: full gen + script to remove anything besides reusable models
other projects are sliced by surface area (we could use PowerShell's slicing): gen from those description + script that removes models and replaces imports (each client name needs to be different to allow multiple clients being used in the same context)
success

Investigation for Proxy generation for Request Builders in TypeScript #3642

Description