CE 4.2 Platform Builder Patches MobilePro 900

I probably don’t have the time / expertise to actually follow through and try this out but I just thought to ask:
Since the MobilePro 900 is capable of custom ROMs (a la Cmonex), is it possible to use Platform Builder for Windows CE 4.2, update all possible hot fixes for Windows CE 4.2, build an image, then replace all changed files in the ROM?
Then the MobilePro 900 would have the latest possible updated CE 4.2 ?

Or if that’s not possible :
Which Core .dll files are able / worth updating and they can just be drag and drop replaced after normal OEM ROM install ?

Yes if you can supply platform builder with all of the BSP configuration and driver files to make it work on the SoC.

At the time of its release, the Mobilepro CE.NET 4.2 had all the latest components. We never had access to the BSP for the 900C. The different drivers in the custom flash ROM are really components from other devices that came out later...and some of them were customized for those machines. Some were extracted from the machine's ROM, some from OS update installation packages.

More than once I've tried a newer/larger/smaller driver only to find it incompatible with the 900C. As far as Microsoft goes...they really never introduced significant 4.2 updates and just went on to CE5. I could easily flash my Mobilepro to CE5 if I had the available RAM...which I don't. 64MB of persistent memory is the reason why. Sure would have been nice to have swappable socketed memory chips...

I think torch means all of the Platform Builder QFE's rather than going to CE 5.0 - https://www.microsoft.com/en-gb/download/details.aspx?id=19477 - which is another 4 years of patching and fixes.

In theory if you can dump all the DLL's and registry from a stock device/custom ROM, plus work out the boot loader configuration integrations, you could.

Correct, it was more a thought project I'll keep in the back of my mind, but yeah, I meant to integrate all QFEs for the CE 4.2 updates into the ROM proper.

Is there certain .dll files I could just randomly update? Kinda like Core .dll patches but won't bork the install?

There are, but good luck getting them out of the QFE file without a full PB install.