I have tried that. In the file index_skin.xml I changed the expression
That seems to help prevent the activation of the gyroscope for my Android devices, but I did not have the chance to see if the gyroscope still works now on an iPhone or iPad. The tour in which I have tested this is located here: "http://virtualtours.nl/sluis" (which contains work in progress).
If this works, it would be something to implement in a next version of PtP. Or better still, the next version could have a new version of the gyroscope code that works for Android.
Gyro works on an ipad on the link you provided.