yes they do.
i believe the queen's wrath and iron banner enforces this by giving you bounties in which you have to equip shader, mark and emblem to increase XP gained upon cashing in your bounties.
hence the reason all factions have certain emblems you can only purchase upon reaching level 3.
level 3 emblems give a higher tack percentage than level 1 emblems.
i think it stacks like emblem lvl1 - 8%, lvl 2 - 10% and lvl 3 - 12%
mark - 8% - 10% depends on whether it's legendary or rare
and shaders adds another 8%
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Care to try it out with emblem, I know events do it. But not sure with regular factions and Eris