Area effects already exist and are in fact ancient and had been used for power transmission etc. in the past but are very laggy. Mostly not used for this anymore at least in Abh but small parts still do due to less lag and convenience (ignores restrictions and infinite power) like in Kroom's.
If you mean by continuous a lingering effect then they do lack that specific feature although it is possible to do this and had been done by other means. In this case, it would need a life time and a frequency parameter. Needless to say this will lag x-times based on the products of the settings.