I know, it's crazy... My DM insisted that Warblade's level 1 Weapon Aptitude ability lets it work. And I think he's right:
You also have the flexibility to adjust your weapon training.
Each morning, you can spend 1 hour in weapon practice
to change the designated weapon for any feat you have that
applies only to a single weapon (such as Weapon Focus). You
must have the newly designated weapon available during
your practice session to make this change.
It's clearly meant for fighter bonus feats like Weapon Focus and Specialization, but... Yeah. This book is crazy, huh? Not taking anything from it this time around, character is complicated enough already.
See, I'd parse those lines to specifically refer to the Focus and Specialization trees both because they reference weapon training (which is explicitly what those feats are -- you've spend so much time working with that one weapon type that you're flat out better with it), and because they specify the "designated weapon". You designate a weapon when you pick Weapon Focus (Soup Ladle) or whatever, when the RAW say "Choose one type of weapon". Lightning Mace doesn't let you designate a weapon, it flat out tells you that you only get to use one weapon type.
It's like Weapon Finesse: having that feature doesn't mean that you can spend an hour training and then apply your Dex to attacks with a Fullblade. Could someone suddenly be able to use Deflect Arrows while dual-wielding daggers? Use Crossbow Sniper with a non-crossbow ranged weapon? Improved Natural Strike applied to manufactured weapons or Unarmed Strikes? Vae School for a weapon that isn't a whip or spiked chain?
So on and so forth. We've got a decent selection of feats that apply specifically to one type of weapon or attack which is not determined by the player, but by the author of the feat. I mean, if the DM's going to just shrug and let people go crazy, have fun with it, but I'd sure as hell not allow it.