I wish i'd seen this er....5 years ago? LOL....
I kept thinking there had to be a better way to do nursing bras for me. I hated hated HATED all the nursing bras I could find in my size (at largest was 36J) and stumbled across the cami with builtin bras, maternity, and loved them for being around the house and nursing. I could shove a whole prefold in there in lieu of wearing nursing pads. He!

but the skinny straps hurt my shoulders and once I dropped a few cups I had to tighten the straps quite a lot and made it harder to get my boobs out.

no chance of it now, but if I could do it again i'd make (or at bare min, modify) a cami with a wider strap like you did, do either a eyelet, Dring, or fabric strap and pull strap through and use poly snaps to set high and "low" so I could flip my breast out easy to nurse.

ah well....live in learn eh?