Yeah, I mostly use them as cheap cannon fodder, to be honest.
I still think the mass produced ones show up to randomly, too rarely. Last run I needed to go to the fifth system and only then found a place to pick a construct - just to find out that not a single mass-produced construct was among them. So I completely canceled the otherwise great run and had to start over. Pretty frustrating as I am just trying to unlock that commander.
My least favorite faction is the trade union, by the way. I understand their strategy and purpose, but prefer to quickly move in and waste the enemy instead of slowing the opponent down and have fights that drag on endlessly. Further, in deck-builders, I generally dislike factions that function well only based on an additional resource (cargo in this case) that otherwise is not of any use in the game. I always think that this unnecessary complexity is not needed and no fun whatsoever and those factions fall flat for me because of that.
Edit: found a way to cheat me into getting a mass produced construct. If there isn't one as one of the three options, just quit to the title screen and reload. You get a completely different set of construct options.