<rant mode on>
I don't know what for the distinction between channelstrip types is any good, but we have this silly (sorry ...) system since Logic channelstrip settings were invented. We are not allowed to load audio settings to a bus without any reason from the users view. I would even like to load a certain instrument setting to an audio channel, why not? It wouldn't load the instrument itself but why not the effect plugins?
<rant mode off>
Yes but this is a only a small issue for a programmer. At least I think when everybody is able to handle this problem in the environment just by adding 1 to the slot number, it should be a no-brainer for a developer.For example, even though the pop-up menu on a software instrument track is in the middle of the channel strip, it is, I believe, internally still the first plug-in, as it was back in the Logic 4 days of "Audio Instrument" tracks. So in this case, adding an Instrument setting on an Audio track would result in a completely wrong order of plug-ins-the first audio insert plug-in would be an instrument, which obviously wouldn't play.