Microsoft.Identity.Web's built-in MsalMemoryTokenCacheProvider (registered via
services.AddInMemoryTokenCaches()) exposes a virtual GetSuggestedCacheKey(TokenCacheNotificationArgs args)
method that looks like a natural extension point for customizing the cache key (e.g. to partition
by audience/resource, in addition to the default homeAccountId / ClientId+TenantId key).
However, this hook is not actually invoked when using the standard ASP.NET Core DI-based