Not sure MJB about whether the tubes in the 332 can be rolled. The tubes in the 332 are in the input stage and consist of a 6N16 Tubes and a 6N15 Tube. You can reach out to Audio Advisor which sells the Vincent line and they should be able to answer your question.
The SP-332 is an evolution for the SP-331 and all the product information I have indicates it is strictly a AB amp. There is a very similar sounding Vincent amp call the SP-331MK which cost a few hundred dollars more and which does operate in Class A for the first 10 watts.
If Class A operation interests you, there is a new Vincent Integrated amp called the SV-700 which is a tube/solid state hybrid like the SP-332 amp but offers the user a choice of Class A operation for 50 WPC or Class AB for 100 WPC. There is a button on the Integrated that allows users to choose the mode of operation,