Photonicat 2 Debian image forces nvme_core.default_ps_max_latency_us=0, but public mainline bootscript does not

Hello Photonicat team,

I am testing NVMe power management on a Photonicat 2 running Debian.

On the shipping image, /boot/boot.scr contains:
nvme_core.default_ps_max_latency_us=0

As a result, APST is disabled at runtime:
nvme get-feature /dev/nvme0 -f 0x0c -H
-> APSTE: Disabled

However, your public mainline repository
photonicat/rockchip_rk3576_linux_mainline
contains scripts/photonicat2.bootscript without this parameter, and build-base.sh generates boot.scr from that script.

So I have a concrete mismatch between:
1) shipping Debian boot.scr
2) public mainline Photonicat2 bootscript

Questions:

1. Is nvme_core.default_ps_max_latency_us=0 intentionally forced in the shipping Debian image for compatibility?
2. Is APST expected to work on Photonicat 2 with the public mainline Debian image?
3. Does the M.2 NVMe slot support runtime PM / D3cold / RTD3 on current hardware + DT?
4. Which image / branch should be used to test NVMe low-power states correctly on Photonicat 2?

My current test SSD is Samsung 970 PRO.
I can also provide:

• /proc/cmdline
• nvme id-ctrl -H
• nvme get-feature -f 0x0c -H
• dmesg for the PCIe/NVMe probe path

Best regards,
Vladimir