I believe the upgrade machine you are referring to is the preFIX service offered by AspDotNetStorefront, which is a SaaS version of the software that is always up to date. Part of the preFIX offering is a one-time onboarding to your new mobile-friendly store.
The onboarding service is run by Vortx and works on non-Vortx hosted websites but requires your site to be publicly accessible. The service is secure and reliable and there is no lose ends that have to be manually fixed. The service provides you with a new responsive look and feel that requires customization to keep the look and feel of your existing site.
Below is a link to the preFIX service provided by Vortx,
I hope this information helps,