Written
There are several ways in which the JavaScript Validation files (and the CSS files can be enabled or disabled. Here's the logic used in CFv4 RC3.4
IF 'Load ChronoForms Files'* is set to 'Disable Completely' then load nothing. ELSE IF EITHER (a) 'Enable JS Validation' is set to Yes OR (b) 'Auto Detect Settings'* is set to 'Yes' AND The string validate[ is in the Form HTML THEN Load the files*
* On the Form General tab
** Which files depends on the 'Load ChronoForms Files' setting; either 'All Files' or 'Necessary Files'.