this is basically a repeat of this question from a month ago with more detail
On 15 June 2020 Raspberry Pi promoted the USB Mass Storage Boot functionality for Raspberry Pi 4s to "stable". Raspberry Pi users are still required to edit which firmware they'd like to load from "critical" to "stable" but it is an otherwise readily available feature.
Biggest question: What is the timeline for Ubuntu to support the newly promoted "stable" firmware which allows for USB Boot?
Alternatively, has anyone sussed out the right configuration edits to make to force it? I was able to get to a
U-Boot> failure point after having copied
start4.elf and some other config files from a USB-booting Raspberry Pi Buster install but cannot seem to get past the
U-Boot> error where it seems to not be finding my devices or ethernet.
Any information on expected timeline for getting USB boot into the official imager or assistance getting with a bootable configuration to an Ubuntu 20.04 imaged installation would be much appreciated
EDIT: there is this comment from what appears to be someone on the Ubuntu team. No timeline is given and the implication seems to be it won't be anytime particularly soon.