Set a registry entry thus:
[HKEY_CURRENT_USER\Software\Microsoft\Microsoft Image Composer\Settings]
"MaxUndoLevels"=dword:00000010
I had to actually create the entry, but YMMV.
I was amazed that this worked. Why this is not a default or at least a configuration option is beyond me.
Update: Another annoying issue: When you have windows Display Settings Scaling set to a size other than 100% you will find that the color picker does not work correctly. Mine was set to 150% and this drove me nuts for a while. The fix is to move the window to a display with scaling set to 100%.