I've been using the notable since around a week into the league, and it felt slightly off to me the whole time, but after reading other users' experiences with the notable I began to suspect that it worked quite differently than originally stated.
Background:
Seeker runes: 25% increased damage with brand skills.
Unattached brands gain 20% increased brand attachment range per second.
As most know, the strength of the notable is that this increased attachment range, once gained, lasts for the duration of the brand, regardless of whether it reattaches later.
The notable stacks with multiple instances of it in your passive tree from jewels, like all other cluster notables. For all of my mapping and testing I used 2 of the notable.
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The main issue I found stated among many brand users is that, for those with a low cooldown Brand Recall, the notable seemed to stop functioning, or at least its effect was noticeably reduced.
After a lot of testing, I found that the reason for this is that Seeker Runes' increased attachment range
does not scale with how many seconds the brand has been unattached. At least, not exactly. Essentially, rather than considering how long the brand has been alive, the rune considers only how much time remains before the brand disappears. The
'lifetime' (max duration) of the brand is in practicality different from the brand's
age due to the brand's duration being constantly refreshed by 1.2 seconds per brand recall cast. Essentially, it seems the calculations behind Seeker Runes use a shortcut - rather than spend all the effort to track the brand's history, it simply subtracts the brand's
remaining 'natural life' from its normal natural lifespan, then grants 20% increased attachment range per second of that value (or 40% with two of the notables). This means Seeker Runes disregards the age of the rune. For example if the natural lifetime of the brand is 14 seconds, as with my build, and in this specific instance, will expire in 4 seconds (not considering interference from Brand Recall) then you get (14-4)*20% attachment range, or a total of 200% increased (400% with two notables).
So what are the implications of this?
With a brand recall cooldown time equal to or below 1.2 seconds, Seeker Runes is completely useless, assuming you constantly refresh your brands. While the brands' age could by anywhere as much as 20 minutes (for example), the calculations only consider the fact that the brand is currently sitting at the very beginning of it's natural lifespan, and thus is granted no extra range through the calculations. My personal recommendation is to use a Brand recall time equal exactly to
1.2 seconds. (any lower cooldown and you will 'rejuvenate' your brands, slowly healing them and reducing their range). This can be achieved with a level 7 brand recall linked to a level 4 empower and level 3/4 second wind in a pair of +1 socketed gems gloves (with Heirophant ascendancy). At this point Brand recall with neither rejuvenate the brand nor allow it to age. At the beginning of the map, cast your brands and wait until they are one second before expiring, then hold down brand recall for the rest of the map. This will give you the maximum benefit of Seeker Runes (in my setup, for example, 520% increased attachment range) throughout the rest of the map. Alternatively you can use a brand recall with a slightly higher cooldown (forgoing or de-leveling the second wind) to allow your brands to slowly near the end of their lifespan, thus allowing you to 'cast and go' instantly at the start of a map, at the price of getting reduced SR effectiveness for most of the map and eventually having to recast your brands.
The most interesting thing I found throughout all of this, and the most difficult part to test, is that increasing brand duration/skill effect duration leads to a greater bonus from SR. For example, if I socket a 20/20 increased duration support into my main link setup (not recommended!) the brands then have a lifespan of 21.4 seconds unattached, or a potential total of 840% increased brand attachment range.
tl;dr
Seeker runes takes a shortcut in its calculations, disregarding how long the rune has been unattached in real time and instead only considering how close the brand is to disappearing, regardless of interference from brand recall. This renders the rune more and more useless the closer your brand recall gets to a cooldown of 1.2 seconds, meaning you have to choose between not having to recast your brands and having the effect of the Seeker Runes notable.
