Endgame labyrinth map drops

Endgame labyrinth only seems to drop shaped T1 maps for me. Has anyone else experienced this?

Finally found a normal T1 map as well. I wonder why the shaped version is so common though? Maybe the monsters try to drop higher tier maps according to their level and my atlas bonus, but the labyrinth's map drop pool is populated by T1 maps only, shaped or not, and it somehow gets rounded to the shaped map which is T6? Could this be a hint at what happens if you get a map drop for a tier for which no maps are unlocked?

I did labyrinth a few times and grabbed the emperor's charts. Results:

Shaped crystal ore: 14
Desert: 7
Jungle valley: 2
Arcade: 1

I don't know why desert was so popular, but shaped crystal ore is way off the charts. It makes up 58% of the drops - more than twice its share. How is a tier 6 map able to drop in the labyrinth anyway? And why only the shaped map? Is it intentional or an oversight from the shaping system?

Even if it's not intentional, perhaps the endgame labyrinth could be changed to drop maps equal to a T8 map? Anyone running it is way past the point where T1 maps are of any real use. Would it be so unbalanced to allow useful maps to drop?

I am also dropping about 75% shaped maps in the uber lab, over quite a few runs. Most of the rest are random T1's. Twice I have opened Emperor's Maps, both times I got 3-4 shaped Arcade maps, and one T1, and no other higher level maps.

Makes me a bit concerned about "bricking" my atlas, as shaped maps are not as desireable as normal ones from an atlas progression viewpoint.