This is the part of which i am working to understand,
@DaisyJane and why i reached out to you for further understanding. (Recognizing the amount of time /study you have put into ideas of suffering, disability and championing for the rights.
I recognize the language that we use for "putting down" pets, for example tends to be about their suffering. In our family, it is about their pain but, also, with pets there isn't the ability to get input from them when they are well.
I would like to be "put down" at the point where my suffering has reached a particular point. In some diseases, such as cancers of other than the brain, most people are able to communicate. In other words, Humans do have the ability to get input on where they are , and that continues as diseases progress. Diseases that you mention that are degenerative, such as dementia, ALS, are items which cause particular challenges due to the inability to communicate at the point where people's predetermined factors exist in their bodies.
In other cases, such as when a person's life changes dramatically due to an event, I sense that there may be suffering of the individual., whether it be extreme physical pain, or mental. As @kimmio mentioned, that may require time for adjustment, and so, i get the protection around that, to ensure that the individual is appropriately aware and has had supports to be able to not just survive, but live.
So, with something that is a degenerative disease, what is reasonable, and where would people consider the point that they would say, they no longer wish to survive. How reasonable is it to do that in advance?