I was able to reproduce this in my lab and you are right, when creating an Inspection Settings exception any gateway that does not have the IPS blade enabled won't appear as selectable in the Install On field. This is the case under both R80.40 and R81 management, so it is not a visual glitch in the SmartConsole GUI on R81. To me there is no clear technical reason why this would be the case as Inspection Settings are supposedly fully part of the Access Control blade in R80.10+, but there may be some obscure limitation concerning Inspection Settings exceptions that still require some kind of hook through the IPS blade since Inspection Settings were once a part of that.
This is the kind of limitation I'd expect to see for exceptions concerning the oddball 39 Core Activations, but exceptions can be added for those regardless of IPS blade status no problem. In my opinion the ability to create Inspection Settings exceptions on gateways where IPS is disabled is being improperly blocked by the SmartConsole GUI, and this limitation does not seem to be documented anywhere that I can find. Tagging @Dorit_Dor.
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