As Pete mentioned, the 10-hour seeker timeout starts over with each new upgrade. That was an unforeseen side effect of the way ship upgrades are executed… but I think I’ll just roll with it (I’m still not entirely sure what will happen if you upgrade while you have a seeker in your inventory). If you haven’t used the seeker much in PvP, I encourage you to do so when you eventually unlock it. It really is a game-changer and totally worth the wait.
Aside from the obvious utility when you’re looking for a gold-heavy bot or other potential target across the quad, following an xwarper, etc., you can also launch it at a cloaked ship in the immediate area to gain a strong tactical advantage. When used in concert with magnabuoys and standard buoys, you can often render an opponent’s cloak completely ineffective.
So while on one hand it kind of sucks having to wait so long for a seeker in the already insanely powerful Tier 2s and 3s, it is also nice that seekers are few and far between…especially when you’re flying something slower or with less than a full minute of cloak available.