On a hunch, I took a look at the Denso injectors used in the L5P 6.6 Duramax. Their design is identical to the updated LWN injector, so as I suspected it's not a Bosch injector with the rest being Denso. At least, this is all assuming the image for the updated LWN injector is correct/valid and not a generic injector image just grabbed from another part for reference. Which seems somewhat likely at this point since there are basically no other references and nobody has actually bought the updated part to compare or even pulled injectors from a 2019+ to compare to the originals.I really, really doubt this is different for passcar, but their purchasing departments really do have more clout. But in general FIS are systems. You cannot use the pieces a la carte. So if you want Bosch injectors you have Bosch fuel pump, rail, lines, spill......and if you want the controls, Bosch computer too. Only that last part is negotiable provided you are doing all of your own software and controls then.
To change from one FIS to another would mean a complete new development. You have to run all sign-off tests, durability, and reliability growth for the new FIS from the ground up and then certify. It's practically like making a new engine.
"Updated" LWN injector - 2019-2020 GM Fuel Injector 55504598 | TascaParts.com
OEM Denso injectors for the L5P - L5P Denso OEM New Fuel Injectors | InjectorsDirect.com