> Shouldn't happen just at the whim of the PM. A sane environment would work by a developer asking for help first, and it actually sounds odd that you have capacity for a PM to throw someone to just 'hurry up' tasks

The problem is that if the PM decides to do that, the developer has no authority to refuse that.

> Any PM who says features are set in stone isn't doing their job. A PM's role is to handle change and execute the plan. Sounds like weak management.

Most PMs are just proxies for business, they manage up and out but not down. They will not risk their jobs by refusing requests from business, in the long term that would put them in an unsustainable position.