This got so long it no longer fit in the replies 😭 so re: your last comment:
Hmm... honestly, it rather feels like you're ignoring the points I make, so some quotes to back up what you're saying would be appreciated. don't get me wrong, you're free to headcanon what you like, but to claim the fandom gets it wrong yet ignore canonical quotes that don't fit with what you say feels a little...
Just so we're clear: Dan Heng's memories as Dan Feng are CANONICALLY unnatural and caused by tampering, as told to us by Jing Yuan on why he banished Lingsha's master. the quote above about healing arts to restore Dan Heng's memories of Dan Feng IS Jing Yuan's
that said, I'll try to adress your claims on this topic point by point:
"ie the thing that would have stripped dan heng of his powers had it been done correctly" do you have a quote on that? as far as I'm aware, we're still by and at large ignorant on what the exuvation charm entails, exactly - and even less about whether the reincarnation of a high elder would keep the power of their previous life should they be unable to complete the succession ritual before the end of their life. All we do know is that the exuviation charm was excruciatingly painful, so it might just have been outright torture to force Dan Feng into an egg, as injury can trigger hatching rebirth prematurely.
"We have no evidence of anything else being done to affect his rebirth." to be fair, it's unclear if what Lingsha's master did affected the rebirth itself or just his memories after the fact, but that did, indeed, happen. other than that, Dan Feng's rebirth was forcefully induced, but we're not clear over how that might have affected his reincarnation.
"As far as we know, the only way Dan Heng differs from any of his previous incarnations is the lack of healing powers, and you could argue that was due to tampering," I'm not arguing, I'm giving you the quote where jing yuan TELLS US Dan Heng having Dan Heng's memories are a byproduct of tampering. (and personally, I think that the split in powers was an accident - I can't agree that Dan Feng planned it.) That said:
"Dan Heng's memories are fragmented, just as you described" ...are they? do they seem difficult to interpret to you?/gen. there's an entire department charged with transcribing and annotating the High Elder's dreams, yet Dan Heng's memories seem remarkably clear and easy to understand - the people involved, their place in the timeline... Besides his memories being canonically unnatural, I feel the main point of divergence between Dan Heng and every High Elder ever is that Dan Feng's memories do not come only in dreams - the clearest example of this is the sequence about drinking together in Ichor of the Two Dragons, but Dan Heng remembered how to open the sea, how to reseal it, etc, while he was awake. besides, the only memories he seems to get are of Dan Feng, not any other high elders, which I'd think is unusual too.
Personally, I think it's reasonable that speculation runs so rampant in the fandom - the lore is...very confusing lol. and sometimes outright contradictory ("the xianzhou doesn't engage in torture" vs what they did to dan feng and hoolay, the flawed exuviation charm vs what was caused by lingsha's master, some logical assumptions being regardless disproved with new info, etc.). I...didn't intend for this reply to get so long lmao, feel free to ask for clarification if you like