Mine has performed adequately for detecting incoming storms hanging vertically indoors, from a hook up high on my living room wall.
I've been tinkering with an AS3935 sensor board as a side project, and its sensitivity and detection range seems to be direction-specific. From looking at pictures of the innards of the Acu-Rite sensor, my $0.02 is to place it with the LED's facing the direction where the bulk of your t-storms come from. In this area, LED's facing WNW is detecting storms with the sensor indoors before I can even hear the thunder outside. (I bought the outdoor Acu-Rite lightning sensor from their replacement parts site and not part of a complete package, so I don't have the console to see the actual distance or strike count that it is reporting.)
Oh, and I actually did an outdoor test with an AS3935 stashed in that Acu-Rite solar radiation shield on Wednesday evening. Being inside the shield did not appear to have any noticeable impact on detection sensitivity.....