How to build Component preload for Launchpad Plugin by tooling?

Hello all,

I'm developing a Fiori Launchpad Plug-in and I intend to put its repository in a CD pipeline soon. Like a UI5 app, Launchpad Plugins also have a recommendation to Provide a Component Preload file for runtime (Plug-in Development Guildelines on Help Portal).

The problem: WebIDE neither provides a UI5-cli or Grunt file to build Preload by tooling when creating a new FLP Plug-in project.

Question: Anyone out there had success to build preload for Launchpad Plug-in by tooling? Any hints would be helpful.

I'm currently trying to make it buildable in UI5-tooling based on files that work fine for UI5 apps. I had to do a minor change in resources\configuration\paths property since FLP Plug-in have everything on root folder, unlike a UI5 app that puts them on webapp. I'm doing this build test at GitLab pipeline with this ui5yaml.txt and this packagejson.txt (renamed both to txt to allow upload) with a fresh clean FLP project with the commands:

npm install --global @ui5/cli
npm install
ui5 build

The build fails precisely at task generateComponentPreload with a bunch of Unexpected token error (job log exceeds 4MB). This can't be a error from plug-in itself because it was just created from wizard, and works without errors when testing, and both files for UI5-cli looks OK for me.

Best regards