Upstream has released version 1.6.0 on 2026-07-27. The current
Debian package is 1.3.1. Below is a summary of changes since
1.3.1:

1.4.0 (2025-02-19):
 * FLEX: Estimate total offset based on estimated passed full
   cycles
 * FLEX: Suppress timestamp via --flex-no-ts option
 * FLEX: Fix for group messages
 * Timestamp UTC ISO-8601 mode
 * Add JSON output (partial)

1.4.1 (2025-02-23):
 * Update man page to reflect latest changes

1.6.0 (2026-07-27):
 * Added GSC paging support with error correction, auto-polarity,
   batch messages, and JSON output
 * Major FLEX_NEXT improvements based on ARIB STD-43A, including
   more robust decoding, message reassembly, validation,
   timestamps, and JSON output
 * Improved POCSAG polarity detection, BCH error correction,
   charset support, and malformed-message handling
 * Added FLEX and POCSAG generation, native macOS audio capture,
   automatic input format detection, and optional SDL3 oscilloscope
 * Improved CMake, MinGW, and automated test support
 * Fixed FLEX group-message bounds and other decoder issues

Upstream releases:
https://github.com/EliasOenal/multimon-ng/releases

tags 1144333 + patch
thanks

A packaging update for 1.6.0+dfsg-1 is ready for review:

  Salsa MR: https://salsa.debian.org/shadowcaster3/multimon-ng/-/merge_requests/1
  CI: passing (sid/amd64)

All changes mentioned in the original report are included.