If you want to make other reg files into nLite addons to pre-integrate
use OnePiece Reg2Inf - https://www.wincert.net/forum/topic/9409-tool-dx-tool-x86x64/?tab=comments#comment-121332
Open up the INF file created with Reg2Inf and insert the INF entrys below [registry_addreg] into the template like the above file.
https://www.wincert.net/forum/topic/7560-please-help-how-to-make-a-addon-that-will-apply-registry-tweaks-before-windows-starts/
https://www.nliteos.com/addons/index.html#registry_addreg
You can make a nLite addon for this to insert the registry entry into install media registry.
1. Make a file called Entries_POSReady.ini and put in the following contents
;=======================================
; Entries_POSReady nLite Addon Registry Keys
;=======================================
[general]
builddate=2019/11/10
description=Entries_POSReady
language=English
title=Entries_POSReady
version=1.0
website=
[registry_addreg]
HKLM, "SYSTEM\CurrentControlSet\Control\WindowsEmbedded\ProductVersion", "FeaturePackVersion", 0x0, "SP3"
HKLM, "SYSTEM\WPA\PosReady", "Installed", 0x10001, 0x1
2. Zip the file into POSReady_Regtweaks.zip
3. Add the zip file as addon into nLite