Need help concerning release channels and TestFlight

First off I inherited our companies app. Upon my first submission to test flight, I was horrified to learn my test build went into production. Talking with the original developer, his response was “huh…that’s weird”. I think he had been releasing to production directly to avoid testing.

At any rate, much reading later I realize that the default behavior is to enable the OTA updates when building in the default release channel. So I am trying to build and release in “test” channel so that our team can test without affecting production.

What I need is confirmation of my understanding and your absolute guarantee that my test build won’t make it into production (<-- joking of course, but please confirm my understanding).

So, I have created an eas.json file with the sample release channels of development, preview, production. I’ve performed a build with the preview release channel (i.e. expo build:ios --release-channel preview). I can see this build has the correct release channel in the builds section of my expo account.

First question: Since it’s not in the “default” release channel…this should not have affected production…correct?

Now, I invited teammates to my account (should have been an organization but that’s for a different discussion) in the hopes that they will be able to install from the build listing there. Can they install from there? I am not seeing an option other than download.

What I really want is to push that “preview” release channel build up to Apple’s TestFlight. That is how they are used to accessing the build. But…I am ascaredyfraid. If I push that build up to test flight, can they test without affecting production?

Then, once everything is tested, in order to push it live, do I just build in the default release channel and let expo do an OTA update of the app? Or should I push another version to the app stores? I know that if items that normally end up in the binaries change (i.e. sdk versions, etc.) then I need to push it to the app store. But if only the javascript changes, I can use the OTA updates…correct?

I’m completely new to Expo, so these may seem like basic questions. I just need confirmation on what I am reading.

Thanks in advance!