Sorry, the thinking in the comment 3 is wrong.
This MNRM put ERS effect in (1, -1, -1, 1) slopes of theta. It can't reflect to any parameter in RE-RSM. Perhaps It is more similar with the Kuan-Yu's model that put a person slope at item category parameter. The ERS in MNRM directly affects the probability of each category even if the threshold disordered appears. When ERS is very large positive value, the probability of 2 and 3 categories will be close to zero.