If you install Firefox Focus and make it your default browser on Android the Jerboa client (and others I think) will use it when loading links unless you have a specific app associated with a given URL (e.g. NYT app, NPR app, etc).
If you’re not familiar with Firefox Focus it’s a version of Firefox built for privacy. It basically makes it so that every URL you load behaves like a private browser tab. It also has ad-blocking built in which is sweet (though it doesn’t work on everything/not as good as uBlock Origin).
Oops: Just realized your question is related to Mastodon and not Lemmy. Though I’m certain that Firefox Focus would work the same way for Mastodon clients.
Actually, I just checked Tusky and yes, it does load URLs in Firefox Focus. So my advice is still good 👍