That didn’t seem right, so I just went and looked – they do have it in maple and cherry. Maple is out of stock, but I would imagine it’ll be back in stock soon.
I wonder if your spray adhesive is actually interfering with your masking adhesive? I’d try sanding and then using straight masking material, it should stick quite thoroughly. The smoother the material is, the more it’ll grab on, I mean try taking medium-tack masking to acrylic, it holds almost too well. Sanding your ply and getting all the dust off will make a huge difference.
This is what I use, and I have very little trouble: