If you're going so far as to install Lineage, couldn't you take the small step further and download alternate browsers to change the user agent? (Unless the default Lineage browser can do this already.)

I run a Google'd OS for now but I haven't used my bank's terrible app in years and years. I use their terrible website via desktop mode instead.

Well, to add insult to the injury, this bank does not allow website login without the mobile app. Which is absolutely infuriating. I did mention that on my comment :-)