A neni to kvuli tomu, ze VBA kod je single-threaded? Pak by se to GUI nemelo jak prekreslit, kdyz se spracovavaji ty rozsahy (pac je blokovane jedine vlakno).
EDIT: Mrkni sem: https://msdn.microsoft.com/en-us/library/office/gg 264522.aspx
EDIT2: Pripadne sem: http://stackoverflow.com/questions/27145201/cannot -interrupt-running-operation-in-vba-when-command-b utton-is-being-pressed