The bracers of archery are an uncommon magic item that state:
"While wearing these bracers, you have proficiency with the longbow and shortbow, and you gain a +2 bonus to damage rolls on ranged attacks made with such weapons."
If I'm a level 3 Warlock with the Improved Pact Weapon Invocation and I conjure a Shortbow as my pact weapon and cast Eldritch Blast using the shortbow as my Spellcasting Focus, do I get to add +2 to the damage roll(s) of that Eldritch Blast?
No, bracers of archery provide its bonus to ranged attacks made with a longbow or shortbow, however using such a weapon as a spell focus is not the making an attack with the weapon (you're nor not using the bow as a weapon).
The bow is a weapon. You are using the weapon as a focus (not with EB, though). Q.E.D. the ranged spell attack is a ranged attack made with the weapon.
Well that's really strong then, considering you can roll Eldritch Blast damage 8 times per round at level 17 (in combination with the Sorcerer's Quicken Spell), that's 16 damage.
I don't see any ambiguity. If you have a class ablity that lets you use a weapon as a focus, you are NOT using it as a weapon. You are waving it around in the air like a wand.
It's like using a longbow as a walking stick. You can use it like that, but bracers of archery don't give you a bonus to your ability to walk up a hill.
I don't think anybody would argue that it's RAW
What you're using it as doesn't change what it is though. The bracers don't care how you use the weapon, only that the attack is made using said weapon (in this case (well not this exact one) as a foci).I don't see any ambiguity. If you have a class ablity that lets you use a weapon as a focus, you are NOT using it as a weapon.