I can see a case there.
On one hand, a player that sacrifices 1 Fortune at character creation to have +1 Attribute point has exchanged that FP for at most 1400XP (because max Attribute is 14). If the player used it to get +2 E and F of a Skill, it is at most 2000XP (because max Expertise and Focus to that use is +3, according to the paragraph describing the option)
To me, that seems like buying those XP in advance. I would say that buying that FP back costs 2000XP and that it’s only allowed if your new total is 3 or less.
That way, 2000XP later, players that didn’t chose that option and players that did can have the same stats. It is still probable that the ones that sacrificed the fortune have less stats, if it was to raise an Attribute to less than 14.
On the case of Sorcery, CRB also includes permanent Resolve loss for learning a spell, while The Book of Skelos (page 75) includes a way to recover that Resolve. It fails to include a way to recover sacrificed FP, though, which speaks against allowing it.
Regarding the idea that it is an intentional mechanic to avoid players creating a large amount of magic items, earning 2000XP means 7-20 4-hour sessions, averaging 10 (because average per session is 200XP) Recover the cost of each enchanted item your sorcerer makes costs you the XP earned in about 3 months of weekly gaming.
It also costs about 30 Gold per success or Momentum of the spell (10 times the cost of a normal enchantment, if I understand Everlasting Sorcery correctly) CRB 308 recommends no more than 15 Gold rewards per adventure, of which about 5 go to your own Upkeep. I can see those 10 sessions been used for three very successful adventures that net you 30 Gold and, again, your sorcerer used all the experience and physical rewards of 3 months of gaming to store an spell with a single success in an enchanted object.
The at least 2000XP that costed your sorcerer to get the talents to actually enchant something could also be considered, as could the Resolve cost that learning the spell in the first place (since it is permanent Resolve, meaning you’re easier to scare that any of your companions)
I think that all those costs can compare with another character gaining 2 points in two skills and buying a suit of full plate armor.
All considered, it takes your sorcerer a couple years of weekly gaming to create 3 enchanted objects of actually very little power (remember, we considered the cost for a single success on the spell) and doing nothing else.
Regarding that “the limitation is not necessarily applicable to NPCs” I really don’t like that idea. If you PC is a warrior or a merchant they can very well be the best around several nations, Conan the King includes mechanics for your PC to even rule a land, but your sorcerer can’t be as good as NPC Sorcerers and that is a conscious design decision? No, I really don’t like the idea.
I’m no expert on 2d20 but afaik there’s no other game with permanent Fortune sacrifice. For instance, Mutant Chronicles doesn’t have that Character Creation option, so I’m inclined to think that really permanent sacrifice is not that intentional. Ofc, I’d like to see the designers’ take on this.