Hi Christina,
How do you want to report on the MSI emails. You can already create email performance reports on sales insight emails. You are right that if you stick then all in one program you won't be able to separate out successes based on clicks and opens from MSI emails However, I don't report on these on the program level. If I want to know how an MSI email did I look at the email performance report. If I want to look at how did MSI emails do in driving registrations to a webinar, I look at that metric differently.
If someone successfully registers and attends a webinar from an MSI email, I use URL parameters and hidden fields to track. That person is a success in the webinar program. The MSI emails will have a unique url parameter with utm_campaign contains either SDR, or sales. Within the webinar campaign, i have a smart campaign that processes if you have utm contains SDR put it onto a list. I can then easily see how many folks became members of the program from this MSI email.
I reserve the use of successes and program statuses when I am reporting on pipeline and revenue. You could theoretically set up a separate program to track success of each MSI email in its own program. The email doesn't have to live within the program. I find that the numbers are low that it wasn't worth it for me but come to think of it you could do that and track each email as it's own program and have smart campaigns to process each of those. Make one, clone it and the setup will be pretty straightforward.