Just tried it with values extracted directly from .mis file as Boomer said.
Two different maps, SAS activator, Zuti's friction standalone mod, no MDS, no any other similar mod. I tried it on areas that was flattened in map_h, not in unlocked FMB.
I must say that I think that I need Zuti's mod, difference in friction on take offs and landings in areas marked with the values in load.ini file is significant. I must conclude that even the values are in load.ini file they are not working without the Zuti's standalone.
Also I believe that Boomer are also in right and that Zuti's mod is not a must. How?
Simply, my airfields are flattened on map_h, and if I'm remembering correctly Boomer said that he flattened his by hand in unlocked FMB. I think that game can't draw at map_h itself (thats sort of hard coded, so to say), but can remember what areas are flattened with tool in unlocked FMB. So, areas flattened by tool in unlocked FMB game sees as flattened and can apply values of friction in load.ini file. But, areas flattened only on map_h game does not see as flattened, they are not "marked" so to say, and just keeps aplying the default values.
So, as I see it, there are two option, one: flat areas in map_h and use Zuti's mod, or two: flat areas of airfields by a tool in unlocked FMB and there is no need for Zuti's mod.
That how I see it, not that I'm 100% sure of that.