Pre-nerf Dhsk had something like 70 DPS close so no it should no it should not be reverted. A slight buff might be OK but its DPS was simply too high.
The maxim I would test having its vet 1 ability scale with veterancy gaining lower reload with each vet level.
And incendiary rounds HMG42 got 80+ dps.
Close range DPS of HMG is as irrelevant as it could possibly be, because that's not the place you'll have your infantry shot at 99% of the time and if it is, you might stop walking up into the arc of deployed HMG at point blank range.
Plus, DSHK had literally all of its stats nerfed hard, not just DPS, making it most expensive and most cost inefficient HMG in game.
I'd argue if maxim or dshk is most useless one for the cost as both do not perform at all.
However, before buffing maxim, I'd first beat some sense into relic and made conscripts actually scale, without that it will ALWAYS be penals or maxim spam into elite infantry instead of cons being supported by a pair of maxims or penals.