Feel free to compare out-of-cover DPS and in-cover DPS of non-upgraded infantry sections. You might find out something interesting.
Their penalties only matter when equipped with Brens, where the cooldown and reload of the weapon is so long that the penalties actually create a difference.
The only "huge buff" they get is the 0.05 target size difference they get when in and out-of-cover.
Yeah and are the IS stuggeling vs Grens\volks to begin with? Are bolstered IS stuggeling vs them? So pretty much, right now you somewhat have to get them into cover to win the engagements consistently, while out of cover its much harder to beat volks\Grens.
This upgrade removes single disadvantage of IS (aside from lack of snare) - performance out of cover and on top of that it provides long range DPS bonus against both mainlines which are supposed to be aswell used at longer ranges and are already stuggeling vs IS at such ranges.
To put it blantly, this upgrade is buffing IS out of cover and it buffs them even more IN cover via DPS increase. If you get default is (bolstered or not) and is with new upgrade and use them identically and how they are supposed to be used, its just a plain fat buff.