>Later in the article it points out that you need to punch holes in your sandbox in order to train the models

You only "need" to do that if you desire the vibe coding experience.

I am perfectly capable, and I often do, download relevant materials for my coding agent to ingest locally.

Often times, the coding agent can't retrieve them programmatically anyways.

AI has ruined that ability for itself. (Nobody trusts anyone to scrape the web any longer)