Moon+ Reader: How do I adjust a highlight *after* it's been made? & landscape?

I like using moon+ reader on my s8 ultra tablet.

When I make a highlight and miss some text that I'd like to highlight, I find that while I *can* adjust the highlight position, it seems to create a whole new highlight instead of letting me adjust the existing one?

Also it seems difficult to make a highlight when I'm in landscape and have the text on both pages, not sure how to get that working.

Any feedback would be much appreciated!