After a frustrating debugging session which turned out to be something with a ProjectName parameter being passed a default, I'm now of the opinion that the default should only apply to commands with -VsTeam nouns. Changing is a matter of a global search and replace of
$Global:PSDefaultParameterValues['*:projectName']
With
$Global:PSDefaultParameterValues['*-Vsteam*:projectName']
I have been doing this successfully on my development branch for a little while but haven't added it to the branch that is the subject of a PR because (a) there may be side effects I don't know about and (b) That PR is quite big enough already.