How to ensure QR code of development server opens the correct app variant when installing multiple app variants on my device?

I followed this expo doc on installing multiple app variants on my device, and it works; a separate app is made with a different name.

However, when I run expo start, the QR code generated opens my production app rather than my dev app.

After messing around with the configs for many days, I realised that the scheme (exp+sotravelapp) in the url generated (exp+sotravelapp://expo-development-client/?url=http%3A%2F%2F<IP ADDRESS>) can be modified by modifying the slug field in the app.config.js file (and subsequently deleting the ios folder (or just Info.plist) and re-building the app).

So this was my workaround:
slug: IS_DEV ? "sotravelapp-dev" : "sotravelapp",

I set my dev variant to have a different slug as well, then re-builded the app with expo run. Now, when running expo start, I include the --scheme exp+sotravelapp-dev option so that the url generated becomes exp+sotravelapp-dev://expo-development-client/?url=http%3A%2F%2F<IP ADDRESS> and the correct app is opened when scanning the QR code.

However, this conflicts with EAS build, as the slug is tagged to each EAS project, so I got this error:

Project config: Slug for project identified by "extra.eas.projectId" (sotravelapp) does not match the "slug" field (sotravelapp-dev).

How can I get this to work even with builds generated with EAS build? What’s the recommended method? Why isn’t this documented?