A direct link to the Extio is here: https://jiangwei.org/download/ExtIO_LimeSDR.zip
The developer posted information along with source code link here: EXTIO.DLL support
I have my LimeSDR installed in a metal enclosure with the 10 Antenna/SMA antenna connectors through one of the face plates of the enclosure. I find that I get poor reception when an antenna is mounted directly to one of the SMA connectors. Using a cable and mounting the antenna a few feet away makes a world of difference for me. My biggest problem as of now is images. I seem to get more of them with the Lime than I do with other SDR receivers I have. I’ll have to invest in a few additional filters.