Allow more 2.5M blocks to be able to "share" the same 2.5M volume

It is easy and useful to be able to place two (or even more) interior wall (flat) blocks in the same 2.5M volume...

I recently encountered an issue with windows

The metal block at the centre is just to make it easier to see what is going on (imagine it gone)

I wanted the flat roof bit covered by a (side) triangle window placed flat in the roof plane, with a window triangle slanted in the area left - replicating the two outer surfaces of that metal block

However you cannot place these block together, this would mean potentially another block would need to be added for this (ahem) corner case...

I worked around this issue like this

by placing a window triangle slanted inverted on a detail block inside that is 25cm lower, frankly this is a horrid work around and looks fugly

by allowing more blocks to fit into the same volume it would greatly reduce the need for a multitude of combination blocks

I appreciate that the two blocks mentioned above although the visual models dont clash some of their 25cm "voxels" are shared diagonally, however if this could be allowed, this would greatly enhance the flexibility of building, ease of use, and reduce G menu bloat...