Hello,
I have a similar issue and it sounds like it could be achieved with a Telemetry initializer, you can filter telemetry items based on their data:
const insights = new ApplicationInsights({ ... });
insights.addTelemetryInitializer((envelop) => {
// Provide your custom conditions under which message shouldn't be sent
const fromChromeExtension =
typeof envelop.data?.errorSrc === 'string' &&
envelop.data.errorSrc.startsWith('window.onerror@chrome-extension');
return !fromChromeExtension; // when false - telemetry item is not sent
});