Handling of multiple co-existing timelines

In some cases multiple timelines are presented in a protocol/design order to be able to focus more on a particular activity and/or to focus on a timing schedule specific for that assessment. This can be handled by sub-timelines. However, there is no directive in where to initiate them:
- Dosing is the most logical timepoint that overlaps but usually there will be assessments before that.
Other specific (sub) timelines can start at screening (like for example a biomarker timeline).

Those timelines that are not the main may also refer to encounters and epochs. Do we allow that and/or can we handle cross-references between timelines in another way?

See example for sub-timelines:


And from IG: