These are the steps to getting Mac UE4.18.2 to build with the correct icons.
- add an blank C++ file to blueprint only project(skip if already using C++)
- replace icon/launch image under IOS tab
- use an valid IOS mobile dev provision profile with dev certificate
- plug-in your IOS device then use the launch to device in editor
Additional steps for distribution build (Must finish development build before proceeding!)
- After dev build is done, change to an valid IOS mobile distribution profile with corresponding certificate.
- Project > packaging . Check for Distribution checkbox.
- package project > IOS
- Can do a quick test by installing to ipad/iphone by installing the IPA file using iTunes.
Hope it helps!