A new unofficial Tasmota firmware that converts Sonoff ZBBridge gateway into a Zigbee router/repeater has been made available.
Sonoff ZB Bridge-Pro - (Manage Up to 128 Zigbee Devices) - GeeWiz
Third-Party Firmware Turns Sonoff's Low-Cost ZBBridge Into a
Sonoff ZB Bridge-p (Pro) to a Zigbee router? : r/homeassistant
REQUEST] Zigbee Router firmware for EFR32MG21 in Sonoff ZBBridge
Third-Party Firmware Turns Sonoff's Low-Cost ZBBridge Into a
SONOFF ZBBridge – Zigbee Gateway for Smart Products – Sonoff India
REQUEST] ESPHome support on Sonoff ZBBridge as a network-attached
Sonoff Zigbee 3.0 USB Dongle from ITead based on Silicon Labs
Sonoff Zigbee ZBBridge - ZigBee Gateway Smart Kit Price in India
Sonoff Zigbee Bridge Simply as a Router in HE - 🚧 Developers
Sonoff ZB Bridge - Device Controller/ Zigbee Hub
SONOFF Zigbee Bridge Pro - smart Zigbee-WiFi Bridge for eWeLink
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Silicon Labs Category - Page 4 of 8 - CNX Software - Embedded