Compact a Classifica​tionPartit​ionedModel

I'm training several cross fold validated classification models on the same input data. I want to save the trained models but each model redunantly saves a copy of the training data in addition to my out of band copy which makes the mat files unmangable.

I've tried

>>compact(trainedClassifers.ctree)
Undefined function 'compact' for input arguments of type 'classreg.learning.partition.ClassificationPartitionedModel'.

I've also tried

>>trainedClassifers.ctree.X = {}
You cannot set the read-only property 'X' of ClassificationPartitionedModel.

Error in classreg.learning.internal.DisallowVectorOps/subsasgn (line 34)
                [varargout{1:nargout}] = builtin('subsasgn',this,s,data);
 
34                  [varargout{1:nargout}] = builtin('subsasgn',this,s,data);

Is there some way I'm unaware of?