Is there any way to split the formatting of a single gallery section (7.1)?

I am a photographer that wants one (grid:simple) gallery section split into two - one half with two columns and a 3:2 aspect ratio, and one half with three columns and a 2:3 aspect ratio. Right now I have two different gallery sections to display my portrait and landscape photos separately. I do not want to have a mixture of portrait and landscape photos in a gallery section with a fixed number of columns, as this will result in the portrait photos being too large. Is it possible to insert a divider into one gallery section and apply different formatting to different parts of the gallery?

One of the motivations for doing this: am trying to use the Universal Filter plugin on these photos to sort them by tags, and the filter only works on a single gallery section, not all of the gallery sections on one page. If it is possible to modify the behaviour of the universal filter plugin to act on all the gallery sections present on one page, this will also solve my problem.

Thanks!

I guess we can use some code to target this. Can you share link to page where you use gallery section?