I use them, but I almost never want to build t2 arti with them (t2 arti generally are very weak), and when I build t2 arti I no longer bother with t1 pgen adjacency (even if im building with t2 engineers) as I usually have better things to focus on than the small efficiency boost provided.
One (admittedly more niche) scenario I regularly use them for is if I inherit a uef t1-t2 base as I can queue up a few sparkies and use them as a low apm way of holding the line, with a much greater tolerance than if I used t2 engis (who die easily if misjudging how quickly the enemy will start to arrive when trying to get the first couple of t2 pd, and can’t be used as aggressively)