Yes! You can switch ignition interlock manufacturers any time you wish. Should you decide to do this you need to make sure that your device removal and new device installation occur on the same day; if you miss a day of service you may be extended up to a year on the program.
It is also important to note that you may incur some financial penalty from early termination of the contract you have entered into with your current interlock manufacturer. They will be able to advise you on this matter.