My Pico is now installed in my new Checkmate A1500 Plus case! Minor alignment issues with the rightmost (nearest the PSU) stand offs, but the rest are OK.
The green LED is dim, but the forward voltage is likely very near the 3.3V drive voltage, giving very low current. Have a look at https://github.com/Neotron-Compute/Neotron-Pico/issues/46
Note: There used to be a link to a video on X - the Site Formerly Known As Twitter - when this post was on Hackaday.io but that video is now lost because it's not downloadable and my account is now closed.