https://www.instagram.com/help/support/privacy and click away the login box with the link at the bottom. I haven't tried it myself, so I don't know if it will work.

On the website select "Yes" -> "How can I get support for a privacy issue from the Data Protection Officer?" -> Click the link at the bottom named "Create Ticket" or similar -> fill out the form.

That's true, but they have a prototype "browser" you can download from their website. And I'm hoping for a fleshed out version in the end, either from them or someone else.

tbh I'm more excited about Servo.org. They're also developing a fully independent browser engine and are funded by the Linux Foundation. Ladybird has corporate sponsors, so I'm a bit hesitant. But the more the merrier I guess.