AES/newspost wrote:

snip

Anyway, I'm assuming that "Jackpot 1243" wanted to move up and down
freely between 39,000 and 41,000 feet seeking smoothest ride and best
fuel economy without having to make repeated requests; and Denver Center
was willing to approve this since nobody else was up that high anyway.

My first instrument lesson in IMC, my instructor and I went to the
practice area and he requested a block altitude of 2000 to 3000 so I
could practice climbs and descents. ATC approved without hesitation.

Allen