Why are you considering these upgrades? Is your Big Turbo build starving for more fuel?
My genuine original tank-pump worked fine with its K04 w/HPFP upgrade and tuning.
The rail pressure target, within the tune, had a max of 140 bar.
I did once try a TTRS-like upgrade...and with it I also added a PM3. Only, that pump lasted under two years; only being able to produce 1.2 bar at full load; at its end. So I returned to using the genuine LPFP and sold the PM3.
If not yet done, you might consider opening the HPFP's inlet "restrictor" to 5mm. This should drop the work-load % of the LPFP. Most report seeing the load % drop from 91.8% to near 80% (±4%).
:
Bamboo fitting restrictor location is on the Left...and Banjo Bolt restrictor location is on the Right; at the beginning of the metal tube leading to the HPFP.