Born from the want to have a better experience for my Panel 4 v5 R36s handheld, and discovering various features not working, along with a lack of support from AmberELEC, this Unofficial build and fan edit specifically tackles issues myself and other owners have faced, along with adding some new features and quality of life upgrades.
and from that, and guessing the AmberELEC guys may not want to support it, due to time and the various projects they are split across, there's also a version for the BATLEXP G350.
I encouraged you to support the AmberELEC developers for their foundational work, and bringing such a stable base to the community to play, work and build upon.
Download from above, or the release page, to your computer.
Use Etcher, Raspberry Pi Imager, or what ever your favorite desk/laptop SD warez might be, to write the image to a fresh SD card.
Keep in mind, the better class of card you have, the more responsive any firmware will be. Best you look out for an A1 or A2 by Sandisk or Transcend.
If you intend to have a dual card setup, i'd go with a 16gb card for the OS and any size you wish up to 128gb (256gb is possible, just play it safe).
For more info on the most recent release and update .tar files CLICK HERE.