I’ve learned this: Custom Keyboard commands files ( customname.xml) are stored in a Folder User Library/Prefs/Cubase 9.5/Presets/Keyboard Commands.
The default Keyboardcommands.xml may indeed be stored in Prefs/Cubase 9.5/ as the link says, I don’t know. But putting the previously-customized KC file into the Presets Folder, in its own folder named Keyboard Commands, made that KC custom set available to me on another machine.
Custom Configurations files have the name given when creating that particular setup. They go, as the linked Resource page says, into Prefs/Cubase 9.5/Presets/Configurations.
I’ve also discovered that the custom settings for Timeline, Transport Bar, Mixer etc can be saved in each of those areas, by clicking on the word “Setup”, then Store and Name as with other areas. I had not realised that, but it may be in the manual. I have just been looking for it but did not find it yet. I did find lots of other relevant info there, but not a summary of the process. No doubt in time I will get the hang of navigating this comprehensive document, but it is too vast to skim, and currently my searches are not generally yielding the result I’m after.
Since most of these settings files have only ,xml to identify, after the custom name, I plan from here on to include in each new filename a clue to where it belongs, eg “KC21Mar18” or Config21Mar18" or “Timeline21Mar18” in case I need to identify the files themselves in the future, eg for importing if they are not part of the Profile or I have failed to save them to the Profile.
Re: Colours - since the customized colours (is this called a Palette?) can be saved as Default for Program, I plan to find the Project (on other machine) with my best colour-selecting and labelling job, open the Project on this machine, and save it as Default for Programme. Presumably this wil override my current customized Default colours.