Data on cable lubricant Chain lubrication is a popular topic. Perhaps for this reason, it is possible to find data for chain friction and chain lubrication. Some of the results of the research are quite interesting. I'm speaking of results such as these:
https://www.ceramicspeed.com/media/3505/velonews-friction-facts-chain-lube-tests-combined.pdf
I have a cargo bike which uses cables for steering. This application is really demanding on the cables, probably more than braking which puts the cables through less motion than steering does. So I really want to lubricate the cables with the best lube. Is there any research like this, with real empirical data, which compares different cable lubricants instead?
A couple of thoughts:

Manufacturers would have the best information about this.  If they are using another company's product, such as when Trek installs Shimano brakes, they generally follow the original producer's guidance; in my example, Trek will generally follow Shimano's advice.  When they vary from it, it's because they have considerable engineering expertise of their own, as well as direct contact with their supplier, and can make very well-informed diversions from that advice to suit their particular situation.  The upshot?  Do what the manufacturer says.
What if the manufacturer doesn't say?  That's more complicated, I suppose.  Cables in general are susceptible to temperature- and friction-related degradation in performance.  A lubricant that avoids those pitfalls is advisable.  One option is powdered molybdenum disulfide (possibly blended with PTFE powder), applied minimally.  It is a powder, and so does not become more viscous with lower temperature.  It also does a great job of reducing friction.

In the end, though, if your ability to steer depends on cables, and you are noticing reduced performance from the cables, they should be replaced.  I recognize that this does not meet your request for data, but I hope it has some value nonetheless.