Yes it’s a good idea.
Some are classed as ‘accessories’ and some are classed as ‘modifications’.
I told the last insurance bod about everything non-standard on my bike and he said some wouldn’t affect the premium ( apart from the fact that they raised the bike’s value and may have a minor effect on the premium) and he was more concerned with stuff that was deemed to improve the performance and possibly adversely affect the inherent safety of the vehicle done by owners who think they know better than the manufacturer (17 inch wheel on a GS anyone..?) … modified ecu ( Hilltop anyone?), exhausts and mods to wheels, braking systems, the list goes on.
Also be aware that the list of stuff you declare on the comparison sites doesn’t necessarily transfer across to the insurance company and may not appear on their system or your paperwork.