As we see there are 2 meanings of “so-called” that can be confused or misinterpreted, of which one implies falsehood and the other doesn’t.
One. to show that something or someone is commonly designated by the name or term specified.
“Western Countries belonging to the so-called Paris club”
Two. used to express one’s view that such a name or term is inappropriate.
“she could trust him more than any of her so-called friends”
Since so-called I feel is very often used to suggest that a title for something describes a meaning that isn’t necessarily accurate, what’s another term that simply expresses that something is titled something without judgment of the title?
Using quotes indicates directly that this is being relayed as something someone else says or said.
It is factual and has less obvious shade than “so-called.” But someone could still say it can be used to cast shade:
This is however irony, where you say the exact opposite of what is meant. So I’m not sure that counts.
But some hint of shade could be unavoidable since any time you report anything as something someone says, you offload accountability to a party not present, and invoke the possibility that that other party is fallible. Hearsay is inherently suspect. Why are you telling me what someone else said? Don’t you know yourself whether it is true?
But I don’t think using quotes necessarily jumps out as a way to mark something suspect.
Pretty neutral. This might work, with the exception of deliberate irony.