ClojureScript :advanced optimizations — keeping JS-interop property names intact without an externs file

I am configuring a ClojureScript build that compiles with :optimizations :advanced via the Google Closure Compiler. The goal is a minified production bundle where calls into a plain JavaScript library — accessed through the js/ prefix and goog.object — still resolve correctly at runtime.

The constraint I am unsure about is the externs boundary. My understanding is that advanced compilation renames properties and strips code it considers dead, so any external API reached by string-based or dynamic property access needs to be protected. What is not clear to me is which of these approaches is the intended, well-supported configuration for a project that consumes a third-party JS library: maintaining a hand-written externs file, using ^:export metadata, or relying on goog.object/get with string keys. I also do not know how this differs between the standard ClojureScript compiler pipeline and shadow-cljs, which I believe handles npm dependencies and externs inference differently.

Assume a recent ClojureScript release; I can verify behavior by diffing the compiled output between :none and :advanced.

1. Is a hand-written externs file still required for third-party JS interop under :advanced, or does the compiler infer externs from js/ usage?
2. Does goog.object/get with a string key fully protect a property from renaming?
3. Does the answer change when building with shadow-cljs instead of the standard compiler?