A workaround for this issue might be :
function setTextareaPointerEvents(value) {
var nodes = document.getElementsByTagName('textarea');
for(var i = 0; i < nodes.length; i++) {
nodes[i].style.pointerEvents = value;
}
}
document.addEventListener('DOMContentLoaded', function() {
setTextareaPointerEvents('none');
});
document.addEventListener('touchstart', function() {
setTextareaPointerEvents('auto');
});
document.addEventListener('touchmove', function() {
e.preventDefault();
setTextareaPointerEvents('none');
});
document.addEventListener('touchend', function() {
setTimeout(function() {
setTextareaPointerEvents('none');
}, 0);
});
This will make Mobile Safari (others not tested so far) ignore the textareas for scrolling but allows to set focus etc. as usual.