For the first time this correlation study compares air discharge CDM and contact-mode Capacitively Coupled Transmission Line Pulsing (CC-TLP) for a large chip-on-flex assembly e.g. for the Internet of Things (IOT) applications. Both ground planes overlap only part of the flexible substrate with long traces. Correlation can be established according to impulse energy and multi-zap wear-out effects rather than peak current. Circuit simulation supports the experiment. A new scanning method yields the potential distribution across the substrate.