Problem: can't use IPMI agent in LLD

[v.goncharov]

I'm create template, with discovery (external check), that returns list of IPMI sensors

{ "data":
[
{ "{#SENSORTEMP}":"System_Amb_Temp","{#IPMITEMP}":"S ystem Amb Temp" } ,
{ "{#SENSORTEMP}":"CPU_Temp","{#IPMITEMP}":"CPU Temp" } ,
]
}

And create item prototype, with:
1) Name: IPMI: {#IPMITEMP}
2) Key: ipmi[{#SENSORTEMP}]
3) IPMI sensor: {#IPMITEMP}

But in items from prototype i get something like this:
Unsupported: sensor or control {#IPMITEMP}@[10.0.0.1]:623 does not exist

How I can set IPMI sensor in LLD?!
Only by external check?! But it takes too long time!