It’s definitely possible to run OpenWrt. If Milk-V did a better job at releasing the source code, like separating patches from the vanilla projects it surely would be less work, but I’ve started extracting those. Overall, the OpenWrt port to get it to boot is definitely not a lot of work. However, the Fisilink switch hardware is controlled by a proprietary binary of which Milk-V has not released the source code.
We can either force that binary to run even on a new image with some plumbing, or possibly reverse engineer at least the initialization part of it. It’s doable, but it’s a great waste of time, especially since the Vega was advertised as open source, but apparently not only the hardware is not, but not even the software.