Allow us to choose the thumbnail image for each map ourselves

Currently Roll20 just picks a random asset from the Map Layer to use as a thumbnail. For people who have gigantic maps (25 x 2000x2000px images for example), like me, this always looks funky. Mostly just showing a tiny fraction of the map and often not enough to actually differentiate them. Is it too hard to let us upload our own thumbnail? Or maybe have Roll20 crop a screenshot of the map to use as a thumbnail?

This is a great Idea, I'd love to be able assign a specific image as the thumbnail. An interim solution: Roll20 picks the largest scaled image for the thumbnail. You can control the specific thumbnail by copying an image you want as the icon and scaling it quite large, then hiding it behind your map.

Support ! And just read Scriptmancer solution, thx for this. ;)

+1 support to this - and thanks for the info on the "how it functions"