Can I upload multiple images at once for use in an image block?

I'm new to SquareSpace. I am creating image heavy posts (10-20 images). Some have captions and I usually want to stack, but may want combine two portraits at times.

I started with a gallery block, displayed stacked. It's the easiest way to upload multiple images at once, but the desired layout and captions require some hacky work arounds.

The image block does everything I wanted, but as far as I can tell, I'm stuck uploading each image individually? Is there a way to upload multiple images at once for use in image blocks or a way to use gallery image content in image bocks?