@PeterJones Thanks for the repro work! I had a strong suspicion that the location of <LanguageAutoComplete> is hardwired (why would it not have been included in <UserLocations> if there wasn’t some reason - presumably technical - for it?)
Frankly, I consider it a Security issue to have user configurable files in %ProgramFiles(x86)% (I’m not alone in this regard!). Now on my machine Controlled Folder Access is enabled and I’m not sure how that interacts with UAC folder virtualisation (VirtualStore) for x86 apps and I’m not about to find out by experimentation. I’ll give it a few days then log a (security) bug.