At the moment, the Course Overview > Timeline (and plugins such as Completion Progress) cannot be utilised with self-paced courses as they rely on static "Expect completed on" dates from the course activities.
I would like to propose an improvement to enable the "Expect completed on" field to be set as a relative value based on:
1. the date of the student's course enrollment (see image 1: image 1), and/or
2. completion of another activity (see image 2: image 2).
As a use case example: I run a number of date based courses and assign self-paced revision/skills builder modules as needed, which students have to complete within a set time period. To help students to know where they should be in the course at any given time is extremely useful in ensuring that they are able to manage their time in completing them.
I have posted this in the forum (see here) and have been advised offline that this functionality is not possible with a plugin and would require a change to the core code.
To be clear, I do not want to restrict or enable access (as an Availablity condition) which can be accomplished through a plugin (such as "Restriction by days offset from start" - although this is no longer maintained since 3.2) but rather I would like the self-paced learners activity completion to be tracked and reported in relation to how long they have been in the course (and/or since their last completed activity).
I have listed below the versions since the new Course Overview block was implemented as affected versions.