In every feature/capability/epic you can specify in the links tab the predecessors and successors.
This valuable information is not shown in the roadmap view.
I would like to have a toggle that:

• draws lines between the predecessor and successor.
• adds additional rows for all predecessors/successor of tickets that are in the current filter

Use case:
We have a deadline in a few quarters. We need to know the critical path (sequence of features defining the completion date). You could argue that this is not very SAFe/Agile, but it is common in our marked to make agreements over a few quarters because the products are quite complex and contain hardware. knowing the critical path is important but we need to not only visualise it but provide alerts so that the user notices when they have a problem.

Advantages:

• visually see if a plan is feasible. A successor that has overlap with a predecessor is not a feasible plan.
• Easier to explain priorities. Items in the critical path get higher priority.
• Easier to explain the total impact of delay if a predecessor delays.
• earlier communication with owners of predecessor tickets that are being delayed.
• owner of predecessor tickets are more aware that delay has impact on a sucessor.
• For the none-SAFe enthousiastics in a company this is a must-have to start using Jira Align.