x o   o x   
            
   x x   o o
            
      o x   

The lace city display shows that this polychoron well is monostratic (in sloping direction), but also can be considered bistratic (in given orientation). Dissecting this non-orbiform polychoron accordingly would not only cut the gybef (at the left slope) into 2 trips, but the whole polychoron gets splitted into segmentochoric components: into traf (upper stratos) and trippy (lower one). That cutting plane there shows up a squippy pseudo facet. In fact, the other way round, this polychoron well can be considered as an external blend of those 2 components.

From this dissection into according strati one clearly deduces that those tets, represented in that display in the central triangle by the left nodes each, has a dihedral angle towards the strati connecting squippy of arccos(-1/4) = 104.477512°, (just cf. traf). But those tets, represented in that display in the lower triangle by the left nodes each, has a dihedral angle towards the strati connection of the same size. Thus the resulting dihedral angle within this external blend comes out to be 360°-arccos(-7/8) = 208.955024°, i.e. from this very angle it follows that this stack of segmentochora comes out to be concave! (The offending margin face is marked by † below.)

Incidence matrix

1 * * * * | 2 2 4 0 0 0 0 0 0 0 0 0 | 1 4 1 4 2 2 0 0 0 0 0 0 0 0 | 2 2 2 2 0 0 0
* 2 * * * | 1 0 0 1 2 2 0 0 0 0 0 0 | 1 2 0 0 0 0 2 1 2 1 0 0 0 0 | 2 1 0 0 1 1 0
* * 2 * * | 0 1 0 0 0 0 1 2 0 0 0 0 | 0 0 1 2 0 0 0 0 0 0 2 1 0 0 | 0 0 2 1 0 0 1
* * * 4 * | 0 0 1 0 1 0 0 1 1 1 1 0 | 0 1 0 1 1 1 0 1 1 0 1 1 1 1 | 1 1 1 1 0 1 1
* * * * 2 | 0 0 0 0 0 2 0 0 0 0 2 1 | 0 0 0 0 0 0 1 0 2 2 0 0 2 1 | 1 0 0 0 1 2 1
----------+-------------------------+-----------------------------+--------------
1 1 0 0 0 | 2 * * * * * * * * * * * | 1 2 0 0 0 0 0 0 0 0 0 0 0 0 | 2 1 0 0 0 0 0
1 0 1 0 0 | * 2 * * * * * * * * * * | 0 0 1 2 0 0 0 0 0 0 0 0 0 0 | 0 0 2 1 0 0 0
1 0 0 1 0 | * * 4 * * * * * * * * * | 0 1 0 1 1 1 0 0 0 0 0 0 0 0 | 1 1 1 1 0 0 0
0 2 0 0 0 | * * * 1 * * * * * * * * | 1 0 0 0 0 0 2 0 0 0 0 0 0 0 | 2 0 0 0 1 0 0
0 1 0 1 0 | * * * * 4 * * * * * * * | 0 1 0 0 0 0 0 1 1 0 0 0 0 0 | 1 1 0 0 0 1 0
0 1 0 0 1 | * * * * * 4 * * * * * * | 0 0 0 0 0 0 1 0 1 1 0 0 0 0 | 1 0 0 0 1 1 0
0 0 2 0 0 | * * * * * * 1 * * * * * | 0 0 1 0 0 0 0 0 0 0 2 0 0 0 | 0 0 2 0 0 0 1
0 0 1 1 0 | * * * * * * * 4 * * * * | 0 0 0 1 0 0 0 0 0 0 1 1 0 0 | 0 0 1 1 0 0 1
0 0 0 2 0 | * * * * * * * * 2 * * * | 0 0 0 0 1 0 0 0 0 0 1 0 0 1 | 1 0 1 0 0 0 1 para
0 0 0 2 0 | * * * * * * * * * 2 * * | 0 0 0 0 0 1 0 1 0 0 0 1 1 0 | 0 1 0 1 0 1 1 ortho
0 0 0 1 1 | * * * * * * * * * * 4 * | 0 0 0 0 0 0 0 0 1 0 0 0 1 1 | 1 0 0 0 0 1 1
0 0 0 0 2 | * * * * * * * * * * * 1 | 0 0 0 0 0 0 0 0 0 2 0 0 2 0 | 0 0 0 0 1 2 1
----------+-------------------------+-----------------------------+--------------
1 2 0 0 0 | 2 0 0 1 0 0 0 0 0 0 0 0 | 1 * * * * * * * * * * * * * | 2 0 0 0 0 0 0
1 1 0 1 0 | 1 0 1 0 1 0 0 0 0 0 0 0 | * 4 * * * * * * * * * * * * | 1 1 0 0 0 0 0
1 0 2 0 0 | 0 2 0 0 0 0 1 0 0 0 0 0 | * * 1 * * * * * * * * * * * | 0 0 2 0 0 0 0
1 0 1 1 0 | 0 1 1 0 0 0 0 1 0 0 0 0 | * * * 4 * * * * * * * * * * | 0 0 1 1 0 0 0
1 0 0 2 0 | 0 0 2 0 0 0 0 0 1 0 0 0 | * * * * 2 * * * * * * * * * | 1 0 1 0 0 0 0
1 0 0 2 0 | 0 0 2 0 0 0 0 0 0 1 0 0 | * * * * * 2 * * * * * * * * | 0 1 0 1 0 0 0 †
0 2 0 0 1 | 0 0 0 1 0 2 0 0 0 0 0 0 | * * * * * * 2 * * * * * * * | 1 0 0 0 1 0 0
0 1 0 2 0 | 0 0 0 0 2 0 0 0 0 1 0 0 | * * * * * * * 2 * * * * * * | 0 1 0 0 0 1 0
0 1 0 1 1 | 0 0 0 0 1 1 0 0 0 0 1 0 | * * * * * * * * 4 * * * * * | 1 0 0 0 0 1 0
0 1 0 0 2 | 0 0 0 0 0 2 0 0 0 0 0 1 | * * * * * * * * * 2 * * * * | 0 0 0 0 1 1 0
0 0 2 2 0 | 0 0 0 0 0 0 1 2 1 0 0 0 | * * * * * * * * * * 2 * * * | 0 0 1 0 0 0 1
0 0 1 2 0 | 0 0 0 0 0 0 0 2 0 1 0 0 | * * * * * * * * * * * 2 * * | 0 0 0 1 0 0 1
0 0 0 2 2 | 0 0 0 0 0 0 0 0 0 1 2 1 | * * * * * * * * * * * * 2 * | 0 0 0 0 0 1 1
0 0 0 2 1 | 0 0 0 0 0 0 0 0 1 0 2 0 | * * * * * * * * * * * * * 2 | 1 0 0 0 0 0 1
----------+-------------------------+-----------------------------+--------------
1 2 0 2 1 | 2 0 2 1 2 2 0 0 1 0 2 0 | 1 2 0 0 1 0 1 0 2 0 0 0 0 1 | 2 * * * * * * oct
1 1 0 2 0 | 1 0 2 0 2 0 0 0 0 1 0 0 | 0 2 0 0 0 1 0 1 0 0 0 0 0 0 | * 2 * * * * * tet
1 0 2 2 0 | 0 2 2 0 0 0 1 2 1 0 0 0 | 0 0 1 2 1 0 0 0 0 0 1 0 0 0 | * * 2 * * * * squippy
1 0 1 2 0 | 0 1 2 0 0 0 0 2 0 1 0 0 | 0 0 0 2 0 1 0 0 0 0 0 1 0 0 | * * * 2 * * * tet
0 2 0 0 2 | 0 0 0 1 0 4 0 0 0 0 0 1 | 0 0 0 0 0 0 2 0 0 2 0 0 0 0 | * * * * 1 * * tet
0 1 0 2 2 | 0 0 0 0 2 2 0 0 0 1 2 1 | 0 0 0 0 0 0 0 1 2 1 0 0 1 0 | * * * * * 2 * squippy
0 0 2 4 2 | 0 0 0 0 0 0 1 4 2 2 4 1 | 0 0 0 0 0 0 0 0 0 0 2 2 2 2 | * * * * * * 1 gybef