SubTickets is really useful - good effort. There's been so much talk about hierarchy, and I'm pleased that someone has delivered a simple solution.
One nice option to add would be blocking a parent based on child status. For me, it would be enough to prevent closing a ticket until all children are closed. I can see other permutations would be useful with some configurable work-flow, but blocking closure would do me fine.
As with TracSubTicketsPlugin 0.2.0.dev-20130507 this seems to be in place. I would want to be able to disable this blocking behavior again; i.e being able to close a ticket in the hierarchy although sub tickets exist which are not closed.