Why don't you integrate the Aux-1 and Aux-2 inputs to control virtual switch.
VS is an easy and reliable method for DC coupled solar system.
The Ignore AC with dedicated gen control would even allow to control the MPPT in case of a Battery / Cell full signal withuout any other external relaying
Assistant are a pain because
- documentation is fairly poor
- every time you want to adjust a parameter in the assistant ( e.g. a threshold ) a running system goes black when assistant is charged
- all conditions are OR connected, it is a pain to program an AND condition for interlocking
the only way seems to be inverting every input and the output which makes things difficult to read and is error prone