SLES15 Unattended Install from USB

I’m trying to create single USB Stick containing Installer, Packages, and autoinst.xml for SLES15 GMC. Only way I have succeeded is to copy contents of Packages iso to a new folder on the Installer named packages/ and then use this media url in autoinst.xml for each package I want: <media_url></media_url>

The UUID of this exact USB stick must be present or this doesn’t work: <media_url><![CDATA[usb:///packages</media_url> won’t work.
So this autoinst.xml file will only work on my 1 stick. I want to create a single iso which can be dd’d to any USB stick and used for unattended installs.

If I dd the Packages iso to its own USB stick, then start the Installer from CD-Rom, when I try to add packages and select USB, my USB stick is not seen at all (because it is iso9660?). If I run yast2 → Add-On Products from an installed SLES15 system, and try to use this same USB stick (dd of Packages iso), it is not detected either.

The SLES15 documentation seems to indicate that a installation is possible from USB (and in the case of the Installer with no packages it is) but mentions nothing about the packages. I suppose it might work if I format a separate USB stick with some filesystem and extract the contents of the Packages iso to it, but then the install requires 2 USB sticks. I’m trying to avoid needing 2 of anything to get this done.

Any ideas?

By the way, using this media_url in autoinst.xml for each package works fine if everything is on a single DVD DL media:

<media_url></media_url>

Just looking for the equivalent (if there is one) for USB since it is much faster than a HP slimline DVD.

solution is to use this media_url tag for each package:
<media_url></media_url>