Add a Due Date option to include "From Account activation" date

Currently, the nearest option that exists for Due Date setting is "Specify a date from user creation date". I work in an agile company, where the time it takes from an account being added onto Access Learning and that person actually logging in varies. We could have a staff member's account be added onto the site a month before their start date, or it could be the day before. The inability to set the due to to relate to when they log in for the first time vs when their account is created seems rather bizarre. It means that those added on in advance could start and have their training already past expiry date!