WalterM140 wrote:

The Brits ignored American advice on how to use the B-17. Admittedly, the
B-17C was not ready for the big leagues.

Could that be why they ignored the advice?

Perhaps.

I'll suggest that there was -no way- given the British experience in WWI that
they were going to the heavy daylight bomber route in WWI. And I don't blame
them a bit for that.

Assuming that your second "WWI" above should read "WWII", I'd point out that the
Brits did go the "heavy daylight bomber route" in WW II, initially and later.
Losses on the early raids to Wilhelmshaven etc. by Wellingtons (both 'heavies',
and reasonably well-armed by the standards of the day) convinced them that
"self-defending bomber formations" weren't. They lacked a long-range escort
fighter at the time, and the BoB delayed any development of same, but they
continued to fly some daylight missions with heavies, within escort range by
Stirlings in 1941 and '42, beyond escort range by Lancs in 1942. The latter were
more in the nature of special missions, but the escorted Stirling missions were
relatively routine. The Stirling was ill-suited to daylight missions against
well-defended targets, but the RAF did give the missions a tryout. And after air
superiority had been won and escort could be provided, the heavies flew an
increasing percentage of daylight missions in 1944 and 1945.

Guy