Got round to doing this. Glow plug removal is easy enough once you remove the inlet manifold.

(Note, the glow plug connectors are not the usual push on/Pull off type You need to squeeze the tops to get them to come off)

Took it for a regen which seemed to go ok (Status active, EGT up around 6-700C etc.)

But performance is still flat occasionally.

What sort of back pressure readings should I be getting using a Launch

(It is not clear what units the launch actually uses, I guess it is lost in the Chinese translation. Currently I am getting about 10 "Units" at idle and around 80 with the engine reved but stationary)