I often don’t bother about deploying temporary apps on their own realm like host. e.g. newapp.brayan.com. I rather chose to deploy them to a sub-path. e.g. www.brayan.com/newapp.
The only drawback that comes along is that Ionic CLI has NOT implemented the argument –base-href so far. Anyhow, you are not missing anything if you are invoking the ng build instead.
ng build --prod --base-href=/newapp/
The only scenario, I could think of, where that could hamper you deployment process, is when you develop with Ionic without using Angular. That is with Stencil (without Angular) for example.