Several balloon-borne radio experiments have targeted the detection of ultra-high energy neutrinos interacting near the Earth's surface. Radio pulses produced by cosmic ray air showers constitute a relevant class of events among the recorded signals. Cosmic ray signals can be produced either by downward-going air showers, where the signal reflects off the Earth's surface before reaching the payload; or by atmosphere-skimming air showers, that reach the detector directly. In this work, we discuss an update of simulation based energy estimation methods for reflected events, as well as an adaptation of this method to atmosphere-skimming events. The performance of the method is evaluated in different scenarios of angular resolution, primary mass and environmental noise.