So am I correct in thinking that at the point of release (assuming Fuji RAW files had been written in DNG format) that the converters, ACR, etc would not have been able to render the file unless it had been converted into Linear DNG, and that if so, then you would still require advanced algorithms to do the conversion into Linear DNG. Is Linear DNG essentially just a DNG wrapper around a TIF file?
I'd think that raw converters written for the full DNG spec (which means LR and ACR, nobody else does) would have been able to render an X-Trans file. However, it might not have been a very good rendering; I don't know what's on the inside of the LR/ACR converter, but it would not surprise me if it had highly optimized code for well known patterns (e.g., Bayer), but fell back to something simplistic (like nearest neighbor) for an unknown pattern.
Linear raw as a wrapper round a TIF file? That's a religious question