Outlook Add-in: Conditional behavior in manifest based on requirement set

Hiya,

I develop an Office Add-in for Outlook that works with the message send functionality.

Outlook Add-ins have two features for message send functionality, the ItemSend ExtensionPoint and the OnMessageSend LaunchEvent extension point.

I'm wondering if it's possible to support both in the manifest at the same time, but conditionally launch one or the other based on the available Requirement Set of the client application? For example, if the client supports requirement set 1.12, use the OnMessageSend launch event, otherwise the ItemSend extension point.

Thanks