I have declared the main stuff that affects the performance of the machine, such as the full exhaust system, braided hoses and so on. I also declared all the security items on there too (alarm, immobiliser, datatag, DNA, Xena disc lock, heavy chain...). Security items display a conscious effort to stop your bike being stolen and if the mods are not all to increase speed, you should be fine.
Things like carbon bits, touring seat/screen, scottoiler... I never bothered mentioning.