Unless it is a single wall rim the spoke heads are of no concern at all. The bigger issue is that the tube is being pushed into the spokes holes of the rim and the edges of those holes are sharp enough to cut a tube. Considering that even mtb wheels run at 30psi require a rim strip between the tube and the rim to prevent the tube from puncturing on the rim I would suspect there's nothing of your setup that wouldn't have the same result. The pressure will force the tube into the hole until it punctures.