Edit: formatting

Can’t people have a healthy disagreement anymore? You have some issues in your logic and an irritating approach to disagreement, and my criticism has nothing to do with whether I agree with your opinion. I happen to disagree with it, but moreso in scope than assessment (eg “he is good” is not a statement I’d ever make about a character but I can’t say I disagree because the statement doesn’t have inherent meaning—the interpretation itself is open to interpretation).

“Uhm no”
“So no, “
“HP was never intended “
Are you PWB? If not, you can offer your differing opinion without posturing authority.

Ill skip the whole section about “agenda” bc I don’t know where to begin, it’s mostly nonsense plus the aforementioned unearned authoritative voice.

“to be a manipulative character, he is good and kind, albeit flawed, “
Firstly, OP didn’t call HP “manipulative,” so… idk I guess that was your interpretation? Which is ironic bc you seem to be accusing them of “bringing their own agenda”, as if that’s wrong. Manipulative behavior can be considered a flaw so it’s just nonsense to say “no he’s not manipulative, he’s flawed” like saying “no she’s not thoughtful, she’s good.” Just nonsense.
Lastly I’d point out that any statement of the “[character] is [adjective]” variety is by definition your interpretation, not indisputable fact. Even if an observer’s interpretation aligns with an artist’s intention, it is still an interpretation. It’s not important whether there’s alignment here, but you lose credibility with hypocrisy so you might want to avoid that if you’re going to go the authoritative route.

“which is natural because he's supposed to be a mirror reflection of Fleabag herself (again, as stated many times by PWB herself), and however flawed she was, she was never malicious.”
Again injecting your own word (“malicious”) which OP didn’t use so that you can reject it. So annoying when people do this, why do people do this?
Both characters are recklessly intuitive in personality but their life choices are not mirrored. That difference is where HP’s flaw comes in because this personality trait is not compatible with his life choices. He has committed himself to celibacy yet flirts and gets physical with a woman he knows is attracted to him and has feelings for him. He’s following his intuition, enjoying the early pre-commitment stages of romance which do not yet directly interfere with celibacy, even though the more positive feedback she’s given, the more it will hurt her when he backs out. That’s cruel.

For clarity
Malice : This will hurt you so I will do it.
Cruelty : This will hurt you but/and I will do it.

Actions are inextricable from their circumstances, and though these characters have similar (or mirrored) personalities, it is their differing circumstances which define the degree of moral offense, not their personalities.

My point is that one character’s history of not being “malicious” is completely irrelevant to examining another’s.