Undo while previewing

I wish pressing Command would not deactivate the effect of Space bar. I want to be able to undo/redo (Command+Z) while seeing the change in the glyph as black (and not having to type a duplicate next).

It is not deactivating the space bar. But Cmd+Space is the shortcut for the zoom tool. Press H to fully select the Hand tool.

I see. The extra step is a bit tedious, but does the job.