Rewriting stream descriptions is a long, expensive, and prone-to-failure
operation. Due to #8061 it may consume a lot of memory. In general, it
may keep failing (and being retried) endlessly, straining the cluster.
As a backdoor we add this flag for potential future needs of admins or
field engineers.
I don't expect it will ever be used, but it won't hurt and may save us
some work in the worst case scenario.
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