Transit: upto 24hrs (not sure how it works for intra US- not that you have any). Stopover can be of any length..as can be the 'gap' between the 2 cities in an open jaw. This subject to the ticket validity- which is 1yr from the date of issue (not a problem normally, as all sectors would be within 1y..but just in case you want to change a date to one later on, once availability opens up).

The 5 stopovers allowance can be used for transits if needed( ie, you can have >2 stops of less than 24h, with a correspondingly lower number of stopovers- not sure if they will just 'allow' or issue the ticket such that a stopover is less than 24h - it can be, just that you'd have to pay the taxes etc.)