These are two totally different things. Expo is an SDK, a build system, and OTA update pipeline (among many other things). It looks like ignite is a set of boilerplates for getting started on an RN project with a particular toolchain (like React Navigation, Typescript, Redux, etc.). Ignite doesn’t have boilerplate for Expo projects, but it seems possible you could generate a blank Expo app with
Expo init, generate Ignite’s “Bowser” boilerplate, copy the JS from Bowser into the Expo app, point App.js to the Bowser stuff, and have the best of both worlds. I probably wouldn’t do this unless you really understand the setup of an Expo project and the setup of an Ignite project, because the copy is a manual process that’s probably going to have a bug or two on your first try.
And… that kind of sums up the limitations of boilerplate. Ignite advertises saving time, and I’m sure it does, but that time savings is largely front-loaded. And, if you really understand React Navigation and Redux, adding those to Expo will not be that hard. The time savings of avoiding Xcode and Android Studio, using OTA updates, etc., compounds over the life of a project.
As someone who has deployed a few apps already, probably the way I would use Ignite would be to learn best practices for adding technologies I’m not as familiar with (in my case, that’d be Redux or Sagas or Typescript) so I then could more easily add them to my Expo project.