5.0 is very stable, you are likely reading about a few users who have had issues that we resolved. But, ultimately this is up to you.
This process hasn't been changed at all in 4.x or in 5.0. Importing GPX and .zip has always and will always be an option. If you are using the same 4.x version yesterday and today, then it is something that iOS itself is doing, not Cachly, we have no way of remotely disabling this option. I would restart your phone and see if the option returns.
You are never forced to update.