Possibility to change multiple values

Yes, same way you do Question regarding creating multiple instances - #9 by akcoder

Its important to note that GenieACS batches everything up. So if your script has 5 different declare's setting the various WiFi params, only 1 connection will be made to the CPE, and all the params will be set in one SetParameterValue (as long as the number of parameters doesn’t exceed the batch size).