> “ There is another problem with locking your sprints. Say you get a new customer ask, it's a potentially trivial but low priority bug. The developer could fix it in a day. But you follow The Process TM, the task gets added to your team's backlog, maybe gets picked couple sprints down the line and does get fixed. But you lost the opportunity to delight the user!”

Nope. That context switching will cost you more on average than sticking to the process. And most often you’ll be wrong about the time estimate, or the customer will be wrong about actually wanting that feature, etc., making the context switch even worse and more costly.