The Belarusian state telecom Beltelecom implements DPI-based protocol fingerprinting plus active probing of suspected bridge IPs. The technical baseline is comparable to RKN. obfs4 with fresh IPs continues to defeat this in practice, particularly when distributed privately rather than via BridgeDB.
BY probing is somewhat less aggressive than RKN probing in volume but uses similar techniques. Bridge longevity profiles are similar to RU. The independent-media ecosystem in BY maintains established circumvention-tool distribution channels that operators can coordinate with.