I think the reason you are not getting any takers is, this is an organisation and diagram management problem, not an OG problem or missing feature.
The human brain can only handle so much information at one time; and if that threshold is exceed, the mind just ignores the whole detail. One large, complex diagram is hard enough to draw, it will be much harder to obtain acceptance. If you are losing track, your diagram is way too big.
Therefore, as an architect, I:
• ensure the each page contains only so much detail, no of shapes, etc
• there is a summary diagram in front, that is a tree, showing each page as a branch
Note that all function decomposition exercises use this same rule.