File associations XML file applies - but still get error messages at first log on

Alright, so I've now discovered this secondary XML file and DLL file in System32, OEMDefaultAssociations.XML/.DLL, having found a post by someone who mentioned this appeared to be conflicting with what they were setting by Group Policy.

It's definitely this pair of files causing the issue in my environment - if I replace OEMDefaultAssociations.XML with the smaller XML file I was using to manage associations by GPO, I get less notifications - and if I rename/remove OEMDefaultAssociations.DLL I no longer get any notifications of the reset associations. If I rename/remove the DLL and apply a separate XML file by GPO as before, I don't get the notifications.

Simply altering the system32\OEMDefaultAssociations.XML isn't enough to stop the notifications but changing the DLL is - so I noticed that if you look inside the DLL there's another copy of the 'default' associations XML. What is this for?! Why, when the XML file contained within is an exact copy of the XML file in system32, does it cause this behaviour? If I copy the XML file to the PC and change the GPO to point at this too, I still get the notifications. There shouldn't be anything clashing - yet somehow there is?!

It looks like for us the 'solution' is to rename this DLL file but that feels like a kludge and who knows what issues it will cause down the line. Can anyone shed any light on this at all, before I implement yet another ridiculous hack solution for our Windows 10 rollout?