Hi,
Clicking multiple times doesn’t do anything. I have done more testing though and the problem only happens on iOS7. Phone running iOS8 and another iPad running iOS8 work just fine. So with iOS7 being a shrinking market you may just decide not to bother. I need some jailbroken features, so that particular iPad won’t be upgrading.
I noticed a couple more buttons that need touchstart added. acf-tab-button in acf-input.js, and acf-fc-remove and acf-fc-add in acf-pro-input.js.
If you need any help with testing just let me know. Happy to help.