Randomize post order / keep big image top left?

Howdy. I’m trying out this plugin and like it so far. I only need to figure out two things to make it perfect for an implementation I need to do.

Right now my grid looks like this:
https://drive.google.com/file/d/1Z4RhZ0HpSlb8AkhAlvi5s5ydQXXBHRma/view?usp=sharing
Where the order of posts is always the same (1—9), and the “larger” grid image could wind up in any position (looks OK except for when it’s one of the last 3 or 4 posts, then it looks messed up).

What I need to achieve is something like this:
https://drive.google.com/file/d/138OSwhXP1MzLhZU92GqL-oqcG7HtY6Ev/view?usp=sharing
Where the order of the posts is random on each load, and the large grid image is ALWAYS at the top left.

I couldn’t find any way to achieve the random order or force the large image top left through the photoblock grid interface. Is there ANY way at all to achieve this?

Thanks.