The patch worked up through vyos-1.3-beta-202108311126. It stopped

Thank you!

Tried the latest rolling. It boots/runs if you give it 768MB of memory.
At 512MB it hangs as before. I guess minimum requirements will be
changing.

I attempted clean installations of VMs using both
vyos-1.3-rolling-202008301444-amd64.iso and
vyos-1.3-rolling-202009011736-amd64.iso. The first image boots up and
allows configuration. However, the latter hangs and never reaches a vyos
command line prompt. The last lines on the boot console are:

Adding that kernel option results in a successful boot. Below is
/var/log/messages from an unsuccessful boot followed by a successful boot
using the kernel option.