How do you use Xamarin.UITest to sign an apk for Android 11?

Question

I want to use a Xamarin.UITest project to test my application (and then upload the test to the App Center).

I am writing code in Visual Studio Community 2019 version 16.9.4 and want to build against the latest Android version.

When I try to run the tests locally I get the error:

System.Exception : Mono Shared Runtime is not supported. This can be resolved by changing the project configuration or using a Release build.

With regards to project configuration:

I get this whether pointing to Android target framework version 11 (latest) or 10.
In the project properties of my Android project (Android Options -> Packaging Properties) as per this screenshot the obvious solution to uncheck the 'Use Shared Runtime' option is not available.
Manually adding the property AndroidUseSharedRuntime to the .csproj doesn't seem to make a difference.

With regards to a Release build:

I have tried running against the .apk built in Release mode on target framework version 10, and it works! But I want to use version 11...
When I have a target framework version of 11, I get this error on the test:

Failed to execute: C:\Program Files (x86)\Android\android-sdk\platform-tools\adb.exe -s emulator-5554 install -g "C:\Users{name}\AppData\Local\Temp\uitest\a-2351CD300830FF81600819C12D0457454DDA69A2\final-9EB410B8BE4AE99B420FA491930368F065D971A1.apk" - exit code: 1

adb: failed to install C:\Users{name}\AppData\Local\Temp\uitest\a-2351CD300830FF81600819C12D0457454DDA69A2\final-9EB410B8BE4AE99B420FA491930368F065D971A1.apk: Failure [INSTALL_PARSE_FAILED_NO_CERTIFICATES: Scanning Failed.: No signature found in package of version 2 or newer for package {com.package.name}] Performing Streamed Install

I've seen a couple of posts about this message (leads here), and Android 11+ needs to be signed differently but I expected (hope) VS would do it automatically as part of its signing with that target version.

So, I have 2 questions - maybe it's an either/or:

Am I missing something in the project configuration that means I don't need to do a separate Release build locally to create the .apk before running my tests?
How can I get Xamarin.UITest to sign the app with the signature required for target framework version 11?