Hi LittleMo,
I love the colors on your quilt top. I think that if you do the starching and LAQ with a medium loft batting that your top will be okay. When I am doing the longarming I sometimes have to really make sure that I have the top as tight as I can get it (without stretching it) to work out areas like yours. I think you will be okay.
Thanks,
Sherryl
Candlequilter