The key aspect here is that Instagram's app is using a Safari Webview but somehow it is injecting its own tracking pixel on the HTML body wether the target webs

The key aspect here is that Instagram's app is using a Safari Webview but somehow it is injecting its own tracking pixel on the HTML body wether the target website had it or not. Which honestly does not surprise me, what surprises me is that Apple allows this. I think there was a time where certain Javascript capabilities were present in Safari but not in Safari Webview and there was certain outrage. Perhaps a solution would be to run the webview through Safaris content blocker engine?