So, I was looking over some feats and found a weird inconsistency with Unmistakable Lore when compared to other feats; more specifically singular skill feats that could apply to a number of other skills:
All of these feats require a certain proficiency prerequisite (Trained, expert, etc.) and gives a benefit to the skills in which you are that proficiency (Quick Recognition only works for the skill you’re master in, etc.). Unmistakable Lore is a noticeable exception: it requires you to be expert in a Lore skill, but gives a benefit to all Lores that you’re trained in, rather than all Lores that you’re expert in. (Another exception being Trick Magic Item, but that’s its own thing.) Meaning that by 2nd level, a character can never critically fail on ANY Lore skill that they are at least trained in.
Now, why am I making a big ruckus out of this? A single Lore is a really narrow area of knowledge, so never critically failing seems decent, but not overpowered. To that, I have two words: Bardic Lore.
The major downside of Bardic Lore is that it quickly falls behind in bonuses compared to other skills, but you still have a decent enough chance of making a Recall Knowledge on something obscure that the party might not have, but you also risk the chance of misremembering (a critical failure). But with how Unmistakable Lore is written, by 3rd level a bard is able to never misremember anything about literally anything—couple that with Dubious Knowledge and that means that they can always remember something about anything. I don’t know about you, but that sounds like serious overkill for only being 3rd level—I’d believe something like that for a legendary-level character, but not for a 3rd level character.
I feel like Unmistakable Lore was supposed to only give its benefit to Lores in which you are at least expert in, but ended up being a weird typo. This may just be me fishing for an FAQ or future errata, but whatever.
Class Feature/Feat + 2 General Feats = always getting at least 1 true info with 1 false info.
So instead of a rare "nothing" you get Dubious result that is just as likely to hurt as help,
and with just Trained +2 you will rarely get the special Crit Success knowledge result.
If you increase Occultism at 15th you get Expert +4 Bardic Lore but the modifier is still below par (proficiency, stat) so not Crit often.
I think you're going to be fine...
I'm personally more worried about having to pull random false info out of thin air every other turn, but that's just a personal problem.
Dubious Info'z:
Resistance/Immunity or Vulnerability it doesn't actually have "I shouldn't use these spells they will be waste"
Regeneration with b$#&%+~% damage type bypass "This weapon/spell usually sucks, but I want to suppress it's Regen, so..."
"Don't attack it with slashing, it can divide like Oozes" (whoops, not true)
Special Attack it doesn't have (Reactions, free attacks etc), prompting useless tactics against it
Movement speed it doesn't have, or is wrong... "it's really slow" when it's really fast... "I can spring attack and it can't get me" ...whoops
Senses it doesn't have (Blindsight etc) or wrong claim it lacks senses it has... "it's light blind? let's move to the bright area..."
It talks a language (when it doesn't) or doesn't talk (when it does), prompting wrong usage of Language dependent abilities or Diplomacy etc...
Really the best is when the true info seems so unlikely it MUST be Dubious Info and the Dubious Info seems like it is real and 100% reliable
(or when the Dubious Info is a type of creature suggesting multiple abilities, while real Info isn't overtly noticeable or specially important)
Sometimes it can be quickly disproved by combat, sometimes it won't be clear from combat.
Sometimes the real info will be superuseful and fake info marginally impactful,
sometimes the real info will be marginally impactful, but fake info can be critically distastrous. Mix it up.
And Recall generally takes an action, so I hardly see it being super common as you suggest.
Maybe for characters who build around it, but then you should be adapting to specific PCs anyways, in whatever area.
But sure, it's something new that takes getting used to and comfortable with...