I came up with better idea how it can still look pretty in the front and a little ugly on the inside, but now have most of the window attached.
No changes at the front:
However this is how it looks now at the back:
Another option, which I don't like too much since it relies on friction, with some elements not ...
It's difficult to tell from the photos exactly how this was done, but here's a window design that is pretty close:
Here's how that's put together:
It should be possible to adapt that rough design to fit in other MOCs.
Could this work in you case? Using snot brick to build it vertically.
The only way I managed to get your angle and snap it correctly is like that.
I used stud.io with collision turned on to be sure it could work.
I hope this can help you.
I found another solution using bar and bar with clip. This one is much more modulable but maybe less ...
Caveat: I don't have this set, so am just looking at the instructions.
It looks like the pins should rest alongside the Axle 1L with Pin 3L you pushed into place on step 294:
You can possibly see that a bit clearer on step 447:
They should therefore rest just in front of the two SNOT assembles you added in step 417.
That's also borne out if you count 12 ...
The piece is 72869 Bar Holder with Clip and 90° Angle (Mechanical Leg)
It's a new part for 2021, and as the name implies, one of it's main uses is as a leg on various creatures. It seems especially well-suited for building spiders:
It hasn't had many other official uses to date, but it does get used as a robot of some kind in the Marvel advent calendar:
As far as I can tell from the instructions alone (available at this 197MiB PDF from LEGO support), the purpose of those particular hinge plates is to serve as bottom support of the 1x12 technic bricks introduced in step 214 (and its symmetrical counterpart in 223). Let me try to illustrate:
So when the subassembly from steps 214-221 is attached, things ...