Do any companies or organisations use IBMs new software development software RBD/EGL?
They can use it, but if it is fresh and new to the market, it is common for large companies to test such applications before using them. Or, if a small company has created a really good product then can ask for testing to the other outsource company, such as DeviQA (https://www.deviqa.com), for example.
If you don’t have to manage any of the methodologies, read up on the Gantt chart https://hygger.io/blog/what-is-a-gantt-chart-in-project-management/. This will help you in the planning and mapping of the processes of technical development of the product. Probably many have heard about management methodologies in software development? That chose you?