…t's near the beginning of the init process. Just set it to the 1 as the default.

…th new SQL looking up the data directly in the associated tables for a given stream writer

…sts will fail at this point

…add some explanation around the rationale

…ike lines on my scrollbar in pycharm)

…xisting_stream()

Without a `stream_positions` table to lean on, this only needed a few small tweaks to
wording and actual representative positions