The only drawback was needing a ~$25 APC smart signaling cable in order to utilize pfSense's Apcupsd server package via Modbus for workstation shutdown signaling over the network but this APC-proprietary cable was not included (the UPS's lone USB port was already occupied by a Synology server).

I am a very loyal APC customer because their stuff just works, and keeps on working

120V LCD SMT750 Compatible Replacement by UPSBatteryCenter, and here APC Smart-UPS 750 (SUA750US

(Plug & Play!), here New Battery Pack for APC Smart-UPS

The only drawback was needing a ~$25 APC smart signaling cable in order to utilize pfSense's Apcupsd server package via Modbus for workstation shutdown signaling over the network but this APC-proprietary cable was not included (the UPS's lone USB port was already occupied by a Synology server).