Godra suggested one of the things I was going to say and that is to set DisableSubscriptions to True, then use the code to set Values
Another option I was thinking, but may be more trouble than it's worth, is to add a SimulatorCom to your form, then set the ComComponent of all your controls to SimulatorCom1. The down side to this is that it simply retains values in memory after writing to a variable, then sending the value back to something that requests the same variable. For instance, let's say you add a meter and set the PLCAddressValue to MyTag. Then you add a BasicLabel and set PLCAddressKeypad to MyTag. When you run the app and click the BasicLabel, you can enter a value. The value will then show up on the meter.
In non-simulate mode, you would change all of the ComComponent properties back to your real driver instance. I have never tried this during runtime, so I'm not sure if it would behave correctly.