That sounds like the popular merc nozzle mod.
I don't think you need upgraded injectors on 99% of tuned IDI TDs though.
On IDI engines the injectors aren't anywhere near as important in making power as in the TDIs.
The 1.9 AAZ injectors should be OK for 60-65 hp apiece - few of us have more power than that per cylinder...
Of course if you need new injectors anyway, then why not.