Alright, just wanted to check. Here's a version that has debug info enabled. Run this and send a screenshot of the chat entries.
Printable View
I haven't tested it with hex grids, and there are a few places I check to see if the map's grid is square so I can do math to calculate token overlap. However, it should work very simply with hex grid. I imagine it will only consider tokens overlapping if they're exactly on the same space (and thus won't work right for larger tokens). I have plans to fix this, but the math is more complex and I will take a bit longer. Probably after the holiday I'll get to this.
New version - v1.2.0
The selector window now opens precisely next to the token that's being selected. Added a new game option that lets you specify where, relative to the token selected, the selector window appears. The default is to the top-right of the token. Tokens in the selector window are now scaled to roughly match how big they are on the map.
Also fixed the issue where multiple small tokens under one big token would not count as being stacked. Now all tokens in contact with the largest token in the stack are considered 'stacked'.
I noticed some weird behavior testing with player side. Non owned tokens come up in the selection list - this should not be. Nothing on player side that is not owned (DB.isOwner(node) or token equivalent) should be selectable or part of the list.
Also noticed some left over windows on player side but don't remember how I got in that state.