@Scott, for sure. Here is a recent example: Netlify App (in this failed deploy the function is being manually zipped per suggestion above).
The only major difference between this site setup and the others (that work) is this one uses the gatsby-parallel-runner package, which requires a Base64 version of the Google Cloud service account credentials via env variable. This variable, however, is not required or used in the function, but would increase the env variable size a bit due to it being larger. I’m not seeing an error message due to this though.