I have found it frustrating for a long time that Firefox for Android only has the simplest settings regarding opening links in apps. It's either; None, Ask Every Time or Always.
It would be much better for me if it would remember which links I want to open. E.g YouTube links in the browser and discord links in the app.
There are similar settings for whitelisting which sites to keep cookies for when clearing all data after closing the browser (at least on Desktop) so I am thinking it would be a similar style of setting.