Great question! I wasn't aware of the 1.24 optimization when I first wrote the post, but was interested to dig into this deeper. I updated the post: https://blog.howardjohn.info/posts/go-tools-command/#digging....
The tl;dr is...: 1. The new caching impacts the new `go tool` and the existing `go run`. 2. It has a massive benefit. 3. `go tool` is a bit faster than `go run` due to skipping some module resolution phases. 4. Caching is still (relatively) slow for large packages