DPP addressing mechanism is only a programmatic way to refer to some data, there are other way of doing so as well, e.g. using EXTP, EXTS etc, in fact you can just change a DPP register need, access data, then restore DPP.
I have found some info here
http://motronic.ws/maptable3.htm, but not sure it is applicable to mored ECUs, I just couldn't replicate it. If at least someone could say if this is true for modern ECUs or note, that would be a huge help.
Thanks.