Pre-approval the CLI tooling effectively enables easier automations around splitting a task into multiple atomic PRs - really great locally but then when you push they just show up as independent unlinked PRs.
Post-approval... they still show up as independent PRs. There's a small nav drop down up top listing the other PRs in the stack but that's it. Literally no meaningful UI changes.
The dropdown also allows you to perform a limited subset if the CLI functionality but this is similar to the ability to edit files in the UI - an optional extra casual use feature that won't be a part of dev workflows: the CLI (or IDE plugins I guess) would be the primary way to perform these actions.
It all left me wondering what the big deal with the preview not being a general release - it's extremely minor optional UI. The stacks cli has been general release since this was announced.