people on here have gotten drop from adept level mech. its possible. seems like total luck anyway as expert 2x did not help.
Eh it definitely helps, it's just that 2x of a low chance is still a low chance. Personally I ran it about 20 times without the 2x drop rate with no drop, and about 10 times with the 2x drop rate, and I did end up getting the drop finally. Who knows whether or not I would have gotten it anyway without the 2x drop.
One thing I found strange is that when I got the drop on Ice, I had run it about 10x with no Mermaid and no boss drop, and finally I got the mermaid and the boss on the same run.
On Fire, it was exactly the same, but in this case it was over 30x running the dungeon with neither drop, and then finally I got both drops on the same run. Definitely a head scratcher there, since I've heard of people getting one drop but not the other, it's weird that in both cases I got both drops at the same time.
One thing I will say is that toward the end of my push to get it, I was getting pretty burned out. And I don't think it was really worth it. I may never even use this thing, there are just so many monsters that have a fraction of the team cost, are easier to level up, and have really good stats. So I probably won't do it again for the other mech dungeons. If I just focus on levelling / evolving my current guys, and saving up Pal pulls for a rare event / chance to get rippers (still need red/green), then that will go way farther and be way more useful than these stupid mech dragons that you can't even use till you're probably rank 100 or higher.