However, the engine seems to hesitate a bit which could narrow down to the regulator.
I didn't have the gauge and connector to test the fuel line pressure, but since renewing the COE for the vehicle, it is "justified" to spend on a new fuel pump for the longer haul.
The decision was to replace the whole fuel pump assembly with original Honda part with the regulator. replacement fuel pump was going around $130-ish but made elsewhere.
The fuel pump assembly is made by Denso.
The existing fuel pump is kept aside for spare.