Vielen dank fuer alles.
The recommended calibrations are in Table 1 Pg 6 of UG570 Rev 0.
"Everything was done with the code being posted." is the answer to the question. The documentation recommends using the driver, and if the driver does everything in this table, then that's a good answer.
And I appreciate that this is an estimate and has no bearing upon my company's eventual implementation - but the answer is in the right ballpark.
I actually have an AD9361 implementation on the desk in front of me which gives us a look at the device behavior in a receiver but doesn't really lend itself to benchmarking tuning speed (the SPI interface is a bit addled). However, I was just this afternoon able to get FASTLOCK to work (using snippets of ad9361.c) and am now getting tuning I can't resolve with equipment in front of me which may be in the 15-20us range you gave us.
So thank you from an EE who's been shoveling software for way too many years. I'm thinking we're in a good place...