Douglas Paterson wrote:

Speaking as a big-iron guy w/ military procedures drilled deeply into his
skull from day one, I find the lack of information on this disturbing....


I sympathize. Perhaps flying from mostly sea level runways has allowed
me some insight as to how much leaning I need to maintain best power
for my airplane. I start leaning on the way up and by experimenting
over time I've pretty much figured out where to set the mixture control
when climbing in high DA situations.

Its an "educated guess" but seems to work although the highet DA
I've actually had to depart from thus far was about 6K.