I've been revisiting a clim project from 15 years ago which was to provide clim graphics to Dan Corkhill's very nice GBBopen blackboard system. I have an initial version now working nicely on Lispworks clim-2.0 on Windows. It is close to running with McCLIM as well.
I have two issues, updating-output appears to work in that the :cache-test is respected but where Lispworks clim calls clear-output-record when a displayed object moves or is deleted McCLIM does not do so. I have attached a simple demo that shows that problem. Just click right or left anywhere in the pane to move the green disk left or right to see the problem.
The other issue is that redisplay-frame-pane (not used in the demo) always causes an infinite recursion that finally results in a blown stack. Part of the problem is with window-clear which in addition to using medium-clear-area, etc to clear the screen also sets window size to zero and then calls compose-space. I have an :around method that avoids that problem but the redisplay recursion persists. My workaround for that is to just call the display function directly but that does not allow updating-output to work correctly.
Paul