I'm not trying to muddy the waters, but I think "intent" is part of this. If they record your call (which they will) and you do your best to explain the list of mods you've mentioned, you've given them every opportunity to ask about them and you've also offered the detail you've gathered from asking people in the know - you can evidence this. This isn't the same position as someone with many mods, who has declared none, and denied having them on a call recording - shown no intent.
With my insurer, they don't care what brand of exhaust I've got or what the bodykit is, they just mark it as "non-standard" and charge me a premium. I declare the lot, because I don't need the aggro if the worst happens and because the price difference is small. The only one they cared about was the remap and the price was governed by the power gains, so 0-10% gains = £xxx, over 10% from stock = more, and so on.
One thing that does occur now, thinking about it. Would plenum spacer count as induction kit given it's a breather mod?