aside from; whether or not~
Sets aside a topic or condition to focus on the main point, often meaning 'aside from' or 'regardless of'.
This pattern is used when you want to put something to the side—either because it's not the main point, or because you want to say that the result is the same whether that thing is true or not. It often translates as 'aside from' or 'whether or not'.
When attached to a noun like それは別として, it means 'apart from that'. When attached to a verb or a noun plus かどうか, it means 'whether or not' something is the case. For example, 行くかどうかは別として means 'whether or not we go aside'—the main point is something else.
You can also use it to set aside a minor issue to focus on the bigger picture, like 'jokes aside' or 'putting that aside'. It's a common conversational pattern, though it can also appear in writing.