A new image of the Rumored RG353V is floating around. It closely resembles the original RG353 patent so it could be close to real. I expect to hear something official in the near future. Anbernic has been working on this one since last year.
I'm not a fan of the thumb-stick placement on this but I am a sucker for verticals and this would be a more powerful handheld than the 351V. With the same SoC as the RG503, we'd have a vertical handheld capable of running N64, Vita and Dreamcast With No Problem.
Original Rumor:
https://www.retrokezins.com/2021/10/updated-rg-351v-with-dual-thumbsticks.html
Image Source:
https://www.reddit.com/r/SBCGaming/comments/v5xhhx/what_will_rg353v_look_like/