You cant use the vauxhall none dpf update, it won't let you, you will get error.

I would be doing some deeper tests on the airflow and charge side of things, a good pressure test for air leaks and to confirm egr is closed tight, sometimes the standard smoke testers aren't good enough to find leaks, check the turbo actuator is not seized.

Check boost pressure and maf output at wide open throttle, full rpm, compare the results and calculate if the airflow is correct.

Also check the engine is getting up to temperature on the road. and check the gas temperatures are reading correct.

either the engine is producing too much soot, or the ecu is miscalculating the loading due to sensor input errors.

Just my thoughts and where I would start.

Chris