Etiquette for editing a question after it is answered because the answer is more general than than the question

Question

So I asked this question and received an answer that pointed me in the right direction. After a little bit of research I found some additional information including a program that potentially fixes the error. But additionally, the answer solves a general class of problems, not just the specific instance that I found.

I renamed the question to indicate that it answers the general question.

Does etiquette dictate that I add the research to the question or as a comment to the answer (since it was the answerer who did the hard work)? I indicated that the answerer was responsible for leading to the research in the edit to the question.

Answer 1

If an answer gives you additional non-trivial problems you could answer, add as a comment to the answer. The answerer may then incorporate your findings in his answer; at any rate your findings will be there for everybody to read.

If an answer gives you additional non-trivial problems you can't answer, just make a new question and link to the first answer. The questions will be crosslinked in the prominent Linked area at the top of the related questions list.

Answer 2

I don't think you need to bother with it. Will it matter for future people who encounter your question? Probably not, so it's not really useful.

The only real etiquette issue that I can see here is towards other answerers whose answered are suddenly less relevant, and might be downvoted; but that depends on the specific question, and since I guess you refer to this question, I don't see a problem.