Will ConnectALL work when using a tool from a single vendor? How about just two systems to connect? Why not use a plugin in simpler design scenarios?

Yes. Companies often have distributed sites and still want a common backplane to connect multiple projects, even if they are all using one system (e.g. several teams, using multiple instance of Jira in different offices). Think of the product as unifying projects as well as DevOps systems. Our largest customer has over 300 projects. Customers laud ConnectALL for avoiding overburdening the servers’ CPUs, a problem associated with a plugin.