Hi,
I don't personally know how effective your shutdown suggestion is nor can I guess what side-effects it may add but it sounds a reasonable postulation. Given that all the schematics numbered figure 16, 19, 22, 25, 27, 29 and 31 all show only one supply for the Vcc pin and the SWC pin, would it be an option to use a PMOS or PNP to shutdown the whole IC at the supply junction of Vcc and SWC (or would that be problematic for some circuit-related reason, as I assume you may have already considered that option)?