[Help] Customizing Notification Banners?

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The original was posted on /r/androidthemes by /u/counterfeittruth on 2024-01-22 23:30:39+00:00.

So I've been working on a theme for my phone and I want to make custom notification banners for it. I want to change the shape, layout and font, pretty much everything ideally, but I have no idea if its possible or where to begin searching for an app to do it though.

Any ideas? Is it even possible?