THe most common things for reverse polarity damage are
--the phase FETs (which may not outright fail but can be damaged from the extreme overcurrent and die heating thru the body diodes)
--the capacitors (from outgassing / electrolyte damage from the extreme overcurrent and internal heating; sometimes lead damage if they aren't mounted body right to the PCB with very short leads, sometimes they can desolder from the PCB partly or completely from the heat). In most cases the damage to caps, leads, or solder is visibly obvious, but sometimes it just changes the characteristics (ESR, capacitance, etc), sometimes enough to make some definite change to system behavior, sometimes not.
--the first stage of the LVPS (low voltage power supply) that supplies the 15/12/5v etc to the rest of the system. That might just affect the output from it vs the input voltage, or decrease it's efficiency, etc., or other things.
--Sometimes further downstream stages can be damaged if the first stage outright fails. That is unlikley in your case since the controller still functions (which it would not do if the LVPS first stage was destroyed).
--the shunt, if it uses a soldered-in shunt wire (the Kelly I have here has an external bolted-on shunt, as well as external bolted-on fuse; yours is probably soldered in as either a set of manganin wires or SMT shunts), can desolder from the heat, sometimes completely, sometimes partially. One controller I got as a known-damaged unit from a reversal actually had it's shunts burned open.