I believe this should work without any issues. The one thing that springs to mind that could cause problems with stacking and continuous axes is that in order to be stacked the columns have to be on the exact same x-value. If you have columns that are very close but not exact (perhaps a second or so later in terms of x values) then the columns won't stack.
Columns are usually used for data with discrete x-values, so perhaps a category axis where each value represents a "bucket" of date/time values might be better suited to this usecase. If you have to use a continuous axis I'd be interested to know why and possibly see some screenshots etc.
I hope the above helps!