I've worked with Commerce Migrate Ubercart module many times and provided number of patches to make it a great and stable module. So here I'm recently working with Commerce Migrate Ubercart module to add more features :). Actually this came across from a project that I'm working on to migrate some recurring subscriptions from Ubercart to Drupal Commerce including their Authorize.net CIM card on file data.
The Ubercart site is in Drupal 7 and they are migrating to Drupal Commerce. The company is a popular cosmetics company and they have 3 months subscriptions to purchase their product at a reasonable price.
I'm not going to paste any code here since I posted a patch already to module and submitted to the issues queue. If you are implementing similar or learning how to implement such a migrate you can take look at the issue below.
Migrate Card on File data and Recurring Product Subscription data