I would argue that the technical limitations should be considered during the creation of the design doc. In my experience, writing design docs can help me simpl

I would argue that the technical limitations should be considered during the creation of the design doc. In my experience, writing design docs can help me simplify the implementation because I've through through a lot of the headaches ahead of time. But I will say I've seen many projects get ended by customer request or reorg. I think it's a cost-benefit analysis where you should consider the size of the project (and how long it will take to implement) vs. how long it will take to write the design doc. If it's a 2 day task, that is easy to change after the fact, then no need to write a design doc. But if it's a 2 month project that will have public endpoints that other teams or products will use, it likely is worth a 2-3 day design doc.