Yay! "A couple" of projects is even more exciting than 1 project. Are you working with someone or by yourself (or are you not allowed to say)? I'm definitely looking forward to seeing manga you've worked on.
I generally assume anything graphic novel is right to left, because I don't like anything more Western styled, comics and such. So when a graphic novel is left to right it confuses me to no end reading it backwards til I eventually figure it out. I suppose if it said at the start that it was left to right, and was all released at once, or said it every time there was some new pages, I wouldn't mind at all. I just couldn't remember otherwise and every reading session would start with the same issue.
Although I'm used to reading manga right to left, I don't really mind either way, so long as it's clearly stated (if it's left to right). Whenever I read manhua (Korean or Chinese), it usually throws me off, since it's typically left to right, and I keep having to figure it out when the sequence doesn't make sense.
It seems like you've gotten a lot of votes for either direction, I think it's because a lot of readers can and often will adapt to the content. I'm with a lot of people and prefer reading the work in its original layout, whatever that may have been. Since this particular situation seems, for the present, directionless, then I'd just vote on you writing it the way you feel most comfortable.