I always run my firebase projects as monorepos since they typically incorporate several distinct apps with shared deps. I use my own CI/CD pipeline because the apphosting default is not flexible enough.

When deploying apphosting using the CLI, there is a size limit on the zipped bundle. If the "ignore" behavior would allow me to ignore directories from the project root I wouldn't have problems, but since it's relative to the apphosting "rootDir" I don't have a way to use my entire monorepo for integration testing, etc and then ship my apphosting project using firebase deploy because the entire monorepo is too large.