there were extension that did that removed the login popup, theres nothing really you could do about Instagram except get an account and login, thats why I largely stopped clicking on Instagram links especially the fake embeds that opens a new instagram tab.instagram and facebook are as annoyingly bad as twitter in their own way
so good luck with that.
they'll make you login and view it in their app to see replies to shyt. i guarantee you.
if you tie to an IG/facebook account it's over. IG claimed my acocount was fake because all i did was lurk and wanted me to send photo identification to validate my account. they also have their own scrolling limits that twitter is implementing.
there's no way this will be a good alternative.