When creating programs whats the best practice for an email blast that you send multiple times? Not necessarily a drip but a campaign you resend say a month later where all of the assets and list are the same but maybe you do a new blast with a subject line test. Would you create that as an entire new program or just add an email program within that program to do the new send?
Email programs are designed to be one time use programs for sending emails. They won't allow you to send an email more than the one time.
You can house smart campaigns underneath the email program and use those smart campaigns to do your email sends, but then, those would be smart campaign sends, not email program sends.
If you're going to send the second email at a set time after the first one, you could do it in a few different ways. The easiest would be to just use an email program for the first send, then a second email program for the second send. Set up the A/B tests in the email programs the way you want (subject lines) and schedule them for the timing you need.