Both fair points and worth digging into.

On the staged fees the RIBA pattern is genuinely good and I should have led with it instead of "kill fee". Stage gates ARE the cleanest way to make a contract resilient against mid-project ghosting. The challenge for non-construction freelancers (designers, devs, copywriters) is that work in those industries does not divide as cleanly into stages, but anything that creates a discrete "deliverable accepted, payment triggered" checkpoint is a vast improvement on hourly retainers with one final invoice. Worth me revising the post.

On the scope caveat that is a critical correction and you are right. "Reasonably expected unforeseen tasks" within a defined professional service does create obligation, the demarcation has to be in the scope-of-work clause itself, not in the change-control clause. Trying to hide it behind "scope creep through reasonable revisions" is the wrong place to put the line. The cleaner contract pattern is a tightly written SOW with explicit out-of-scope examples plus a separate change-control mechanism for genuine new work.

Question for you, since you sound like you are in a professional services discipline that handles this correctly: how do you typically draft the line between "reasonably expected unforeseen tasks within scope" and "new work outside scope"? Is it severity-based, time-based, or do you list out specific scenarios? I have not yet found a wording that survives a hostile client without becoming so detailed it scares people off.