Freedom UI validators pass attribute as param

Is it possible to pass attributes from a page into a validator as a parameter for use in its logic? I'm trying to pass the Id of the record into an async validator which should then query the database for the record to check whether it is in a valid state to be saved, but I don't seem to be able to pass the attribute in as a parameter and it isn't available by default in the validator. I've tried the below:

					"LookupAttribute_sttlz00": {
						"modelConfig": {
							"path": "PDS.QualifyStatus"
						},
						"validators": {
							"LeadSoldValidator": {
								"type": "Usr.LeadSoldValidator",
								"params": {
									"leadId": "$Id"
								}
							}
						},
					},

But it just passes in the literal string "$Id" instead of the value of Id. I don't see anything about passing dynamic values into validators in the documentation.