Hi Nick! Thank you for your time! I have tried in a zybo and a Z7-Nano (from Microphase) in both I have the very same issue.
What u-boot are you using?
You should be using the ones that NetBSD ships with. You'll find them in this tarball
zynq-zybo-z7.dtb
zynq-zybo.dtb
I have tried using the DTB generated with the Petalinux interface (which boots Linus ok), DTB generated with Vitis based from the XSA, and the ones generated with u-boot for the boards. The only real modification between them I would say is the UART, since the Z7-Nanos uses the uart0 If you need I can send you the dtb/dts files , I’ve checked that the timer in question is not present or with status disable. And yet no avail. Today a member of the reddit community will try in one of his boards to see if he can replicate the problem or get more information. For now I just can say that compiling NetBSD commenting the timers do not compile, and when compiling with all the timers and the DTS disable it or is just not in the DTS, it crashes.
This isn't a surprise. Don't do that :)