Without qso_qslsince LoTW does not answer 'every confirmation' — it answers
with a few recent ones, as a 200 and a valid ADIF. 'All' therefore downloaded a
nearly empty report and said 'matched 1 of 1' on an account holding twelve
thousand. It now asks from 1945-11-15, older than any QSO LoTW accepts.
And the request had two minutes: LoTW spends several of them building a full
account before the first byte, so asking for everything ended in 'context
deadline exceeded while reading body' — a network-shaped message for a
too-short deadline. Twenty minutes, and the read cap raised past the 18 MB such
a report actually weighs.