Sweeps for LO1166/LO2567 under different loads?

I am unable to find any documentation of what happens when you load an LO2567 with 10K vs 600 ohms. Assume typical 1K5/10n Zobel. I know this is a very established topic. Is there much of a difference in the high end?

Trying to figure out whether it makes sense to install 1K2-1K5 termination on the secondary (in parallel to the Zobel) if typical load will be 10K. Advantage to running unterminated is less power draw by the driver — or many drivers in this case, for many channels.

Driver is essentially two halves of an OPA1622 in parallel.

I wouldn’t build the terminating resistor into the box. Everyone who uses vintage 600 ohm gear should have a few cables with terminating resistors built into them, which you can use as needed. You could do the same with your 1.2-1.5k load.  Greater flexibility depending on the job at hand. And there are even times when 10k in where 600 was originally expected can be a creative tool (and vice versa).