It seems planning of "opportunistic" software projects faces related challenges? Though more like research direction exploration/planning, than research produc

It seems planning of "opportunistic" software projects faces related challenges? Though more like research direction exploration/planning, than research production-process management. Gantt is ok when simple time and resource constraints dominate, and there's a simple path. But not all "project-design spaces" collapse that simply. Even small opportunistic projects can have painfully large dependency graphs. "If/when browser bug X is ever fixed", "if I find a better algorithm", "if we get hardware X", "if/when these conditions are ever met, budget this amount of work along these vectors", "we could go this way or that", "here are some associated risks", "possible risk mitigations/explorations", "X is a candidate goal state", "with some path dependencies", "and can pay for this pattern of costs". "Y is an alternative candidate goal state", "this area of project space has a bunch of scattered payoffs", "sweeping this way is sparse on payoffs until the risky big one", ... and on, and on. I've never seen tooling which wasn't ghastly painful for sketching out stuff like this, editing it, and keeping it up to date. I've hope for building something in VR. But perhaps I missed something?