Dell ThinOS 2303 (9.4.1141) and related packages release Friday, March 31st, and are available for download at
https://www.dell.com/support/home/en-us/product-support/product/wyse-wms/drivers
I have tested upgrades on 3000, 5470, 5470 AIO, 5070, and 3040. All were upgraded without issues except the 3040. When upgrading the 3040 best practice is to remove Zoom Packages before upgrading Firmware, not doing so may result in the system not updating and attempting the upgrade again.
First, make sure to read the release notes, https://dl.dell.com/content/manual63938549-dell-wyse-thinos-2303-2211-2208-and-2205-release-notes.pdf?language=en-us
Read more Dell ThinOS 9.4 and WMS Updates are Now available for Download