I won't be buying any more ARM SoCs unless they start shipping with UEFI, ACPI or SBSA like ARM servers do. That includes Raspberry Pis, and laptops and tablets using ARM SoCs without SBSA.
Checkout Tow-Boot, it's not 100% there yet, but I'm using it to EFI boot nixos on a pinephone, granted it's the Alwinner one, not the rockchip one, but still.
Does it still require DeviceTree or custom images? Because that's what I'm trying to avoid, I want to stick with devices I can load any generic ISO on. So far the only thing in the ARM space I've seen are servers.