The problem with XTrans sensor cameras in post-processing is that initially, software engineers had problems modifying their programs to utilize the XTrans array since they were more familiar with the Bayer system. Several companies didn't feel it was worth their while to do so with what they deemed a low volume market. As Fuji sales increased, Adobe and others jumped on the band wagon.
None of the Raw developers are in the least "TWTCHY" as you call it. Some do it better than others and all of them issue new versions from time to time to steadily improve their output.
I have been shooting and RAW developing Fuji XTrans images for a couple of years now and I find the IQ to be better than my Bayer array sensor cameras in terms of color and noise. Sharpness in some cases has been very slightly less than optimal until recently as new software versions are released.
Your comment sounds as if you have never owned let alone processed an image from an XTrans camera but seems to be based on comments of others. I have nothing against Bayer array sensors as I regularly rely on my OM-D E-5M and my Leica M9, both extraordinary instruments capable of getting me '9' scores in competition. But so does the Fuji with no more effort than with the other two.
There seems to be an ongoing argument by forum contributors on all the photographic forums by X trans advocates and X trans detractors as to which is better, Bayer or Fuji arrays. This is only one of the more useless debates similar to comparisons between Mercedes and Cadillac. Both will get you there in style but the experience in getting there is different.
XTrans sensors are simply another way to make the soup. I find that all are delicious and bring me back for seconds. But all have a different flavor; not necessarily a better flavor.