Gamma Knife'd Doffy can outlast Boundman & leave Luffy struggling to stand at the end of it which is more than the Basement Dweller did with his glorious Power Mochis.
Luffy was struggling to stand on his legs when he was just spamming attacks at Dragon Kaido.
He was struggling to stand when he hit Big Mom once with Kong Gun.
I get that Doflamingo managed to hold his own against Bound Man but nothing suggested equality in their battle - unless you can say Cracker is also > Bound Man - let alone, Doflamingo being portrayed stronger than the same mode which almost knocked him out.
At least with Katakuri, we have panels of him directly injuring Bound Man with brute force and DOMINATING the battle, that's the difference.
That's more of a reason to put him above Bound Man than Doflamingo. Even then, it's about overall strength, which includes CoO. But in terms of pure power? Nah, Bound Man was straight up superior.
At best I can say Doflamingo = Bound Man.