Vertical exaggeration in cave maps.
I'm in the process of working on some maps of a world spanning cave network and I've come across an issue with scaling. Any lateral (cut away) map showing the caves on a planetary scale cannot show depth in any meaningful way. Is it considered okay in such maps to use 'vertical exaggeration'? In other words, can I use a different scale for up/down compared to east/west? I'm thinking of something along the lines of 1px = 10km (east/west) and 1px = 10m (up/down) for large scale maps and only going to a 1:1 ratio for small scale maps.
Thanks in advance for any help.