It's worth noting that there is a difference between "has a use" and "is useful." Just because you can drop Spear on yourself in a 4-man dungeon to shorten your Luminiferous cooldown doesn't mean you *need* it for that or that you will notice its effects in the long run. It may end up having an overall negligible effect on the experience. Spear in particular is bad for this in 4-mans because the Expanded Royal Road buff is essentially a loss for your next buff. Spire and Ewer at least give Extend, which is almost always useful, except when you already have the Extend waiting (which is where the RNG can be very punishing at times).