The problem with the current method is that not all Props are created equal. Due to the scarcity of Prop slots, players end up focusing on the ones that add capability to their characters, and not on the ones that add flavor.
I'd say that's props working as intended. Arguably props are meant to be things which add capability... you don't take the clothes on your back as a prop unless you're going to eke some additional advantage out of them (as is the case with armour and formal clothes) but the characters who don't take such props are still assumed to be wearing clothes. Maybe even multiple outfits all covered by the tacit non-prop clothing, or multiple sets of Sunday best all mechanically covered by the one "Formal Clothes" prop*.
I mean, it is conceivable that there might be props which don't grant anything more than flavor. I can't think of any off the top of my head^, but in the case of "flavour items" perhaps the easiest solution is just to rule that they don't take up a prop slot. That way a character can have all the flavor objects appropriate to their character. But then we come to the conclusion I think Crafty have... why bother to list such items on a character sheet? As Alex said,
What *I* don't want is the game to become like DnD with detailed accounting of "stuff" that never really matters to the character's story.
So in the case of spectacles, your character has them for free. They're a background detail which, like ordinary clothes, doesn't need to take up props. That's not to say you can't write them on a character sheet. Make sense?
Alloy of Law is particularly bad for the Prop limitations, as the characters in it aren't Skaa rebels working in secret against an overwhelming foe - they can be expected to have a decent amount of common gear.
I do agree with you here, though I note that AoL contains some of the best deals for prop slots... like the phenomenal Twinborn's Kit (1 Average Metalmind and 1 Misting Vial!!!%). That mitigates it somewhat. Regarding the expense of custom guns, there's always the option of the Gunsmithing stunts, but sometimes you don't want to have the crafting aspect for thematic reasons. What about something like:
Packin' Heat: You gain two free Props which must be a gun or its customizations.
There's still another AoL supplement coming, so maybe we'll see something like that.Footnotes
*There's a counter argument for this and it goes like this: "If "formal clothes" potentially covered multiple possible outfits thematically, then in theory you could lend formal clothes to another character, which isn't mechanically supported because you'd be basically duplicating a prop!" However, this counter argument is itself countered by: "It's not unreasonable that finding something that would fit and suit another character among all your formal clothes would be a Resources roll as laid out in the rules. Mechanically you're doing exactly the same thing as 'buying' a temporary 'Formal Clothes' even though the thematics is different."
^There are a couple which do come dangerously close. "Grooming kit" from the Terris supplement or "Cloak" from the Skaa supplement spring to mind, but I can think of relatively common situations in which they would add a dice, which I would say is the measure of whether something should be a prop or not.
%Of course the risk with Twinborn's kit is that a Misting will take it as a prop instead of a vial so they can burn off the Metalmind Allomantically as free extra charges. I'm glad Crafty trusted us enough to let this prop through even though as Narrators we'd occasionally have to slap a metagamer.