I had some successes moving to kanban project management following github project kanbans. It took me 2 years but management is now starting to come on board. With kanban you can talk priorities (what goes in progress) and future (what goes in "next wave") and budget (how many people we keep on this kanban). The challenge is of course with timelines because while most business timelines are made up, no timelines makes it hard to run a team to ship stuff.

Nice to see it is working for you, on my case it is more adapting to whatever customer is using and leave after a couple of months when all deliverables are done, so there is not really the ability to fight 2 years on something.