Great tutorial, Mike. Very close to what I did in the past using a different plugin and it made me money.
If you're doing A2P sites, try this:
40% Profit Increase for Your Existing Sites in 20 Minutes w/ No Costs
This is just a quick little tweak for existing EPN sites to add a decent additional revenue stream and make it easier for customers to purchase, especially customers who are turned off by price. It has worked very well for me on over a dozen EPN sites. It takes like 20 minutes one time to get it working and there's no cost involved. It's 7 pages so give it a quick read and see if it'll work for your site.
Hope you don't mind a piggyback on your post, Mike.