I kindly ask for extension of Zabbix templates to include monitoring of the most important Rx laser power, which most network devices can detect by DOM/DDM and provide via SNMP.

Reason is same as with monitoring of temperatures, now present in most templates: Detect degrading/failing components before they affect realiability and cause link fails.

I researched switch vendors and all seem to have it: Cisco(CISCO-ENTITY-SENSOR-MIB::entSensorValue), Juniper(jnxDomCurrentLaneRxLaserPower), HPE(hpicfXcvrRxPower), Huawei(hwEntityOpticalRxPower), Arista(ENTITY-SENSOR-MIB::entPhySensorValue), Extreme networks (bcsiOptMonInfoRxPower).

Other switch vendors have it available via CLI/SSH: Dell (show interface phy-eth), Fortinet (get switch modules status), Paolo Alto (show transceiver all).

I even found ZBXNEXT-6320 which is somebody tring to do this for Juniper.