[monocularvision]

This is heavily dependent on whether the app is using a WKWebView, in which the app developer has almost total control over the experience or SFSafariViewController, which essentially provides a mini-Safari with back/forward/reload/reader mode buttons with a button in the lower right hander corner that takes you to full Safari. In the latter case, the app developer has very little customization and cannot see or really control what is happening inside of the web view.

[advisedwang]

You have it backwards: whether an app injects tracking is not a result of whether they use WKWebView of SFSafariViwController. Rather, if they want to inject tracking, they _will_ use WKWebView.