It is worth noting that the Progress Bar for LUT Generation and for Gamut Coverage only starts after any data expansion has been completed.
So, for example, a Quick Profile Grey Ramp RGB profile, with a large number of Grey Ramp points, will be expanded to a 44^3 data set before the LUT Generation/Gamut Coverage calculation starts.
The Progress bar will therefore not start to move before the 44^3 data set has been extrapolated from the Quick Profile.
And that can take some time...
Good to know. Now I won't have to report a bug with the progress bar