Is it OK to have multiple pnpm-workspace.yaml files in a monorepo?

[v-moe]

I have recently run into issues after upgrading to version 10.
The need to explicitly allow install scripts lead me to this discussion about options to allow all builds
I wouldn't like to apply the accepted answer (which definitely answers the original question) to my monorepo, so I came up with a solution that I couldn't find documented anywhere.
I have a structure like

root
-- apps
    -- frontend
    -- backend

When I install a new package that requires an install script I run pnpm approve-builds and it gets added to the root-level pnpm-workspace.yaml which is versioned, problem solved for local development.
The problem is not solved by that alone in Docker though, so I

• put sharedWorkspaceLockfile: false in the top-level pnpm-workspace.yaml
• I add a pnpm-workspace.yaml to apps/backend that only has the onlyBuiltDependencies property, with the same entries as in the root-level workspace file
• in the Dockerfile I just run pnpm i --frozen-lockfile without the --dangerously-allow-all-builds and it just works since there is a pnpm-workspace.yaml in the apps/backend folder.

I am not sure though if this is hacky and if there may be pitfalls, and if this usage is even supported.
If it is, then my follow-up question would be how multiple workspace files are handled on conflict. For the onlyBuiltDependencies a merge strategy could make sense for example but in others not.

Edit
After diving deeper into pnpm's source code and doing some research, I have found this PR: #3464
The NPM_CONFIG_WORKSPACE_DIR environment variable effectively solves the potential problems I can think of.
So, is it part of pnpm's public API? I could only find it here and in source, but not in the docs.