Good evening Kieran,
Thank you for the system information and clarifying what you meant.
You are right, currently there is no way to add more than 1 fieldset at a time.
But I can totally see how that would be really cool and useful.
In fact, you can suggest it or cast your vote on other features in our User Voice forum.
In the meantime, perhaps that could be achieved through some customization.
Perhaps you could hire one of our recommended customizers to do the customization for you.
I wish I had a better answer for you, but for now it’s the best one I have.
Best regards,
Geoff B.