That is untrue, simply compare the Haki in Zoro swords at DR and arround Enma in Wano. That's how much he managed on his own and with Enma.
Zoro hands literally got sucked in due to every bit of Haki being taken out by Enma.
There's a reason, Oden managed to perma scar Kaidou only with one sword evn tho he had two renown ones.
A blade cannot force you to release more haki than you have , enma only forces you to release more than you need .
you probably use more haki in making larger cuts than in just cutting a tree.
zoro getting used to the blade very much implies enma no longer releases more haki than he does intend to since he is not being drained anymore.
again there's a difference between releasing more haki than you can and releasing more than I need/intend to . Enma wont be a powerup if it is draining zoro constantly to make these large strikes and as we have seen this chapter, he is doing it casually meaning its not draining as much haki as it did when he first used it . Nothing suggest the amount of haki zoro put in his blades in dr is the max amount of haki he can use, but is it efficient?
probably not. He has used much less haki with shusui, wado to cut pica, the cliff in punk hazard than he has with enma cutting the cliff. He has to bring it under his control.