Questions

We've implemented a custom navigation pattern for our Bottom Tab Bar to avoid full page reloads on tab switch. All 5 tabs are set to Button Type "Run JavaScript," each calling a global function we've exposed on our page (window.syncBuyNavigate(path), which internally calls our SPA's client-side router — confirmed present in our deployed code via direct file inspection). Each button also calls median.tabNavigation.selectTab(index) afterward.
Despite this, tapping between tabs still shows the app's splash screen, as if the WebView is doing a hard reload/relaunch rather than executing our JavaScript in the page's existing context.
Our question: does the javascript:-URI execution triggered by a "Run JavaScript" tab button run in the same window/JS context as our page's own script (i.e., can it actually see and call a function we defined on window from our app's own code), or does Median evaluate it in an isolated/sandboxed context that wouldn't have access to our page's globals? If it's the latter, what is the correct way to call into our SPA's own JavaScript from a "Run JavaScript" tab button?