When adding a 'Purpose' (or Topic) criteria to a segment, users should be able to also specify a channel.

Currently if you have a general "Commercial Consent" purpose that you use across multiple channels, it's impossible to identify contact/lead records who have opted-in to a specific channel. Instead you have to include everybody who is opted into that purpose regardless of channel, and then rely on the platform to not send if they don't have consent for that channel.

A basic example scenario for where even this isn't sufficient:

I want to send an update message. Ideally I want to send this via SMS if they've consented, however if they've only consented to the email channel then I'd like to send via email. I don't want to send the same message across both channels. This is currently impossible.