Thank you. Do I go to 5.2.5 first or proceed with 5.3.0 after the’enhanced mtd hack’?
You should be able to do the 'enhanced mtd hack' whilst running the 5.2.0 firmware.
I think it's only in the 5.3.0 and later that Hikvision tried to inhibit it.
On the 5.2.0 version - you should also check the contents of locations 0x0C and 0x8000C in mtdblock1 and if the value is 0, change it to 1
The 'enhanced mtd hack' is described in the attachments here : Hikvision DS-2CD2x32-I (R0) brick-fix tool / full upgrade method / fixup roundup.