This article explains how a license works with farms
SPTransformator licenses are locked to SharePoint Farms. As such when you analyze a .sptfinventory and associate your license you will not need to associate the license again if you scan the .sptfinventory file.
You have an .sptfinventory file and there are 10 solutions available. If you were to select a couple of these and analyze and then unlock the results by associating your license.
You then open the same .sptinventory file and select a couple of different solutions and analyze this. You will not need to unlock this analysis as the farm would already be associated.
Modernization | License | Association