I guess to keep things DRY there is a single Private i as Long declaration at the top of the file for all 812 uses of an i variable.

Guess how that falls down? Did you guess that FunctionA in a loop tries to set a Checkbox value vbCheck which automatically calls the Click handler on the Checkbox with its own loops means that the FunctionA loop logic doesn't work because i changed out from under it?

Scope variables should be easier than this nonsense.