I made a custom PCB to attach it to the NanoPi M4 TF card slot. It worked fine.

Now with the new NanoPi M4V2 hardware SDIO clock is cranked up to 150 MHz and I get spurious transmission errors.
On some NanoPi boards, not even the TF card is booted to use eflasher in the console later.
I do not need WiFi so the reason of this higher frequency (as mentioned in the wiki) does not apply to my usage.

Is there a way to reduce the SDIO clock down to the value used on the previous NanoPi M4?