Firefly-RK3399 and Banana Pi BPI-R2 Pro are two mature ARM devices, especially Banana Pi BPI-R2 Pro which offers multiple network interfaces that are suitable for use as a router. However, they are not currently supported by OpenWrt, despite detailed information being available on the official website. We sincerely hope that these two devices can be adapted to support OpenWrt. The official website links are provided below for your reference：
RK3399开发板 Firefly-RK3399六核64位高性能开源平板 (t-firefly.com)
Banana Pi BPI-R2 Pro - Banana Pi Wiki (banana-pi.org)
OpenWrt is a community project and you are encouraged to add support for these devices yourself. You can also donate hardware and hope that a developer is willing to invest time into these devices.
See the following Wiki documentation on how you can do this on your own:
I don't know much about the RK3399, can't really speak towards it. The R2-Pro, however, uses the RockChip 3568 SoC. The 3568 just got mainline support in kernel 6.2, and would have to be backported or you need to wait until OpenWrt moves to that version.
Rockchip in general hasn't played well with Linux in the past. The R2-Pro was an unfortunate evolutionary dead end in Banana Pi's router series. If you look on their site, it's even in a different sub-forum from the rest of their router boards. It's unfortunate they marketed the board as an open-source friendly board.
I'd recommend accepting the pain of replacing it if you have one. The R3 is a beautiful board. The older R64 is a decent choice too. They have also just leaked some info about the upcoming R4 which is shaping up to be another great board, and using MediaTek SoCs which are much better supported in Linux.
Thank you for your response. You are right, I have already made preparations to replace the board.