You may have a difficult conversation to have with the stakeholder. To be perfectly blunt, work with no pressure or stress is called a hobby. I don't recommend you lead with that. What might help is this:

Agile (and it sounds like Scrum would be particularly helpful) focuses on getting work complete through small increments. You start with a foundation idea and build on it. Each piece is complete and shippable. Because each part is completely done and ready to go, you have absolute freedom about what piece you want to do next. This lets you make significant changes in direction down to the very last moment before the deadline. That approach he dismissed is what will give him the freedom he wants.

Another thing from Scrum that will probably help you is a product owner. The product owner has final say on what does and doesn't get worked. Your stakeholder might be the source of the ideas, but having the product owner control the backlog of work will put someone in the middle to ask questions like "what does this actually get us?", "why is it needed?", and "can this afford to wait?"

How you implement agile is a much broader issue than we can really handle hear, but if you get your stakeholder on board with it being the avenue for the freedom he's looking for while still meeting deadlines, that's probably a fantastic first step.

You may have a difficult conversation to have with the stakeholder. To be perfectly blunt, work with no pressure or stress is called a hobby. I don't recommend you lead with that. What might help is this:

Agile (and it sounds like Scrum would be particularly helpful) focuses on getting work complete through small increments. You start with a foundation idea and build on it. Each piece is complete and shippable. Because each part is completely done and ready to go, you have absolute freedom about what piece you want to do next. This lets you make significant changes in direction down to the very last moment before the deadline. That approach he dismissed is what will give him the freedom he wants.

Another thing from Scrum that will probably help you is a product owner. The product owner has final say on what does and doesn't get worked. Your stakeholder might be the source of the ideas, but having the product owner control the backlog of work will put someone in the middle to ask questions like "what does this actually get us?", "why is it needed?", and "can this afford to wait?"

How you implement agile is a much broader issue than we can'y really handle here, but if you get your stakeholder on board with it being the avenue for the freedom he's looking for while still meeting deadlines, that's probably a fantastic first step.