Nothing is really comparable to the DE-10 Nano's combination of capacity, embedded ARM cores, memory, HDMI scaler, and (most importantly) price. The ZedBoard fails the last test: it is a fair bit more expensive than the Nano.
I am keen on the MiSTex project though. The plan is to come up with something that is more flexible than MiSTer to support different targets. So for example, you might be able to target a simpler core to a simpler device and vice versa.
Crypto-surplus hardware with same FPGA, https://www.hivelist.org/@apshamilton/acorn-215-xilinx-artix... & https://www.eevblog.com/forum/fpga/sqrl-acorn-as-an-interest...
Artix-7 is supported by LiteX, an open-source toolchain based on reverse engineering of Xilinx bitstream, https://github.com/enjoy-digital/litex & https://antmicro.com/blog/2020/05/multicore-vex-in-litex/
These can be used for PCILeech DMA attacks/testing, http://blog.frizk.net/2021/10/acorn.html