That's completely ridiculous. You never saw people turn off their mass fabs? I did, plenty of time. It's not hard.
You don't understand that Quantum Gateways are different buildings from t3 factories? Quantum Gateways are "Size 20" buildings, not "size 16", that's the reason why there is a difference (you can add more fabs, so in the end, you would en up being able to have more than 100% discount too easily). You think they are fake but you should rather think they are different
Yeah, I know how adjacency buffs work. The reason why I was so alarmed is because I thought they altered the mechanics in some way so they applied differently to certain units, for instance a land factory receiving a larger buff than a Q-gate when completely surrounded by fabs. However, I checked the adjacencybuffs.lua file and I see that the mechanics are not altered and still work the same way, meaning all buildings get the sam buffs when completely surrounded. Seems legit.
I also see they fixed the power generator weapon buffs, so now T3 Heavy Artillery get ROF buffs from adjacent T3 pgens, which is excellent, but off topic.
Yes, buildings get bonuses for a particular stat depending on the percentage of its perimeter that is covered by a bonus giving building. This makes bigger buildings more expensive to surround with small economic buildings. On the other hand, bigger and higher tier buildings give bigger bonuses, which basically balances it out because it takes fewer of them to surround
a large building.
Also, I still think that constantly switching on and off mass fabs is too micro intensive, and your average player does not have the time to use them in a fast paced late stage game.