PRTG Network Monitor custom sensor - return grouped data

I have an IBM DS3512 storage system that I want to monitor. So far I was able to create a custom XML sensor on Powershell, that grabs performance data saved by smcli.exe (the only known way to reach the stupid storage and get performance data) and creates a multi-channeled XML result for PRTG to display. The main trouble is that the device has quite a number of LUNs, each of them is required to be monitored by several parameters (avg/min/max MB/s IOPs and latency, totaling 9), therefore the total number of channels returned by the sensor exceeds 500. How can I structurize the XML returned so that the data can be listed belonging to a LUN (I'll be fine with 60 groups of 9 sensors each)? I'd like to not spawn 60 separate sensors that would parse one set of files 60 times and retrieve each its own part of data.