How to measure Lead Time for a Scrum Team
The idea of lead time is that when the customer asks for something, a clock starts ticking in their head and that clock stops when they have it in their hands. Therefor, a feature's lead time would be from when the request is received (this usually corresponds to adding it to the backlog) until it is delivered and usable to the requestor. 

Full disclosure, I haven't read Accelerate, but since Forsgren is using an existing term and it seems it's being used correctly, I am referring to the proper definition of the term.

Now, that isn't to say all those other things you mention aren't valuable. They may be. They may even be more valuable to you than lead time. They just aren't lead time.