Well this is in comparison to replacing IP and injectors of IDI to injectors of PSD, as the PSD doesn’t have an IP, although it has an HPOP, which I don’t think is normally replaced with the injectors, but I could easily be wrong
With my past PSD frustration, i definitely think the hpop is on the table for replacement at a similar age/miles interval.
Dont forget things like the IPR, and wiring under the valve covers.
Theres also those injector seats in the heads.... not sure if thats a routine thing, or you'd replace one if there's a problem.