Disabling contracts appears to not be working through a cfg file any more.
As you can see, I have KSS, Base Construction, and Tourism Plus (plus my own cfg that disables rescue and ISRU) installed - but all the stock contracts are are still enabled. (this was on a new install of KSP, and a new save, don't know if that matters?).
THis isn't cosmetic either - I'm being offered stock tourism contracts.
From severedsolo on the forum: