Ecolink Tilt Sensor - reverse open/closed status reporting?

You’re correct, it would required a custom DTH to handle it, something like what this DTH does for Monoprice sensors with the N/C and N/O contacts: [RELEASE] Monoprice Door Window Mailbox Z-Wave Plus Sensor (Recessed/Mounted - 15268/15270/24259) with External Trigger Option and Tamper Device Handler (Official)