However, realistically, a flank with Grenadiers should be as rewarded as a flank with Volksgrenadiers. This means bringing small arms efficiency vs emplacements up and bringing lava nade efficiency vs emplacements down.
I agree with you there - thing with emplacements is that they do need more ways to counter (IE Infantry Flanks) - my only concern is that a low Brace duration overbuffs the current standard counters (ISG/Mortar Barrage Spam or Mortar HT Fire/Flamer HT). Even now a Flamer HT will do significant damage to a braced emplacement and ISG barrage timer is so low that 2 of them make short work of unbraced emplacements. I feel like Brace needs to be more than an off-map counter at at least be a "buy time to mount a counter attack" ability too. Maybe 15 seconds? I suppose you'd need to add a Can't Pack-Up while Braced rule as well so people can't just Brace and then Pack-Up to get resources from a doomed emplacement.