Since you already have both items in game, I have a suggestion.

How about skill hoods be equippable at level 80 in a skill, while only providing a smaller boost. Like 5% for noted or double resources, instead of 15%.

The way I see it right now, the benefits of these things happening when someone hits 99 in a skill is kind of lost.

Not a lot of hardcore skill grinding is going to happen when someone hits 99 in something.(On average, I know there's crazy exp stackers out there that are outliers.)

But if one could reap some of these benefits pre-99, then I think they would be used a lot more.

How many people utilize both a skillcape and a hood from two different trees right now? I only see people utilize the capes for the most part.

Why not have two tiers for this system?

80 seems reasonable to me, the person already committed a substantial time to farming/skilling it, and getting a reduced benefit until 99 would be pretty cool. I think it would add to the economy in a beneficial way, due to noted/double resources happening for people skilling from 80 to 99.