Filtering GeoServer GetFeatureInfo request

I have a 14-band raster stored in GeoServer. I use Jiffle based styles to calculate spatial indices on the fly and it works fine.

But when I clic on the map, GetFeatureInfo request returns the information of all the bands.

The request are like:

server/geoserver/wms/?REQUEST=GetFeatureInfo&SRS=EPSG%3A4326&BBOX=-56.12087982359703%2C-12.437183254414979%2C-56.12083982359703%2C-12.43714325441498&HEIGHT=594&WIDTH=528&LAYERS=layer&QUERY_LAYERS=layer&INFO_FORMAT=application%2Fjson&X=243&Y=263

And it returns:

{
"type": "FeatureCollection",
"features": [
{
"type": "Feature",
"id": "",
"geometry": null,
"properties": {
"Band1": 382,
"Band2": 343,
"Band3": 592,
"Band4": 321,
"Band5": 943,
"Band6": 4470,
"Band7": 5853,
"Band8": 5624,
"Band9": 6089,
"Band10": 6131,
"Band11": 2673,
"Band12": 1208,
"Band13": 3918,
"Band14": 0
}
}
],
"totalFeatures": "unknown",
"numberReturned": 1,
"timeStamp": "2021-03-24T11:18:15.298Z",
"crs": null
}

Is there any cql_filter or something that makes the operation and returns only the spatial index value?