I'm working on support for the MT2500, for now still struggling with getting the stock bootloader to start my image (so we won't have to replace U-Boot and can keep the stock loader just like for the MT3000).
Driver support for the MT7981 is not the problem, Ethernet (incl. hardware NAT/flow offloading) and Wi-Fi (also incl. WED offloading just like on MT7986) all work very well, all at a fraction of the power consumption of a similarly capable x86 box.
The MT2500 is an interesting case because it uses an eMMC and we do not yet support nvmem-cells for MAC addresses (and on other devices also Wi-Fi calibration) to be located on an eMMC partition. I'm working on getting that supported in upstream Linux, see