I take your point. I just read the FA-1027 film developer "Tech Doc" at Photo Formulary, with its probably apocryphal origin story included, and it read more like an advertisement than a tech doc. But Thornton's book Edge of Darkness documents man's life dedicated to the perfection of the high-resolution photograph, so if the developers were good enough to impress Barry and "convert" him, I suspect there's something worthy of praise. I've only tried Precysol, but found it to be very forgiving with roll film comprising mixed subjects and lighting, producing east-to-print images with fine shadow and highlight detail.
We can look (roughly) at the formulation of each but ultimately you’ll probably be on your own when it comes to any sort of practical comparison.
They are all formulated to be staining developers.
Exactol Lux appears to be essentially a low-sulfite, Phenidone-catechol developer with a high pH alkali (carbonate/hydroxide), probably very similar if not virtually identical in working characteristics to Pyrocat-HD.
Prescysol EF seems to be a metol-catechol developer with some glycin as well. Again, low sulfite and carbonate alkali. The characteristic curve may or may not be different than other staining developers.
Dixactol/Dixactol Ultra seem to be more along the lines of the old Windisch catechol-hydroxide developer but intended for two-bath development. They also contain glycin and bromide (to reduce fog). I’m not sure what the difference is between the two Dixactol developers.
None of these are going to be fine grain developers regardless of any supposed “grain masking”. The extent to which they produce finer grain than other acutance formulas is something you’ll have to decide for yourself.