I'm running IOS 11.4 on my iPad Mini 4. I can't update to the new Litchi unless I update to at least IOS 12. Will my iPad work well enough with the update or is it too old and is it possible to update to 12 or do I need to go current to 15. I'm running Go 4 4.1.18 and everything works perfectly so I'm reluctant to update GO 4