OK, I think there's been a slight overlook regarding the bootimg version of KP52 -
There's kernel-power-bootimg, which depends on kernel-power-modules, which depends on kernel-power, which conflicts with kernel-power-bootimg...

Solved it locally by modifying kernel-power-modules' control file to depend on kernel-power | kernel-power-bootimg but I think this should be taken care of asap.