User blog comment:Xenodrone98/Lego Seamoth is DONE!!!/@comment-30446184-20161107160154/@comment-30446184-20161107162006

Fair enough, although I'd recommend that you join. Probably the easiest way to contact the devs.

And on the topic of custom stickers, I've looked into it a bit myself. Here's some advice on the topic from Brickset:

http://bricksetforum.com/discussion/comment/295426#Comment_295426

EDIT: And true, it's not easy. At the very least, you'd have a decent pool of support in the Discord. Having such free access to the attention of the community is something I don't think a lot of projects have the benefit of.