at the moment plugin parameter type COLUMN & COLUMNS with alowed_column_types just shows some red text if the user selects an invalid column type, but I feel it would be better to filter the columns and only show those that meet the allowed types.
From Re: plugin parameter type COLUMNS seems to miss some columns - Dataiku Community there is a work around using Dynamic select using Python.
Note also that the help docs say that alowed_column_types only applies to COLUMN but not COLUMNS however it does apply to both, so help needs updating.
Many thanks,
Pete