Another interesting thing that wasn't mentioned was the fact that Beni Alter trained with KH and got the ability to impose the concept of death which she tried to do on ORT.
Didn't think a Servant could just learn new shit like that, but probably there's some kind of precedent in her lore that allows her to do that .
I think it's due to the nature of KH basically being near Death so much, it's something Beni-Enma can learn due to also being one of the Judges of Death. It's also all but stated that Beni Alter is already stronger than her original, Divine Spirit self so it can make some sense how she can learn imposing death on others like KH can.
And reading it through with Lostbelt ORT, yeah, he did eat the Tree of Emptiness but hilariously, dude was still far too weak and wanted his Heart back lol.
So in the Cliffhanger fight, we fight him at full power from the future that he basically got his Heart and is fully rampaging... but when we fight him, he was still gimped to shit.
Okay, now I find that hilarious, though Nasu definitely retcon'd when ORT landed now, PHH or Lostbelt wise.
EDIT: Though to be fair, he had to make the retcon because otherwise, the premise itself would never work(As there would be no way PHH ORT wouldn't also murder all the humans he know would exist if LB ORT did the same deal. It also makes MORE sense for LB ORT to get angry considering his Heart was removed vs. PHH ORT who would understand heavily it fucked up and actually wait for the "Promised Time" even if some humans fuck with him)