5mo Mal and cats..

I’ve had my pup for about a month and he’s honestly been a dream!…except he wants to kill my 2 cats (ik, ik, that’s pretty much expected). My cats were both raised around dogs and love my heeler mix, but are getting more standoffish to the pup as he acts out.

He’s plenty fulfilled and we play and train throughout the day, so I know it isn’t \*\*JUST\*\* pent up energy. His breeder said he grew up with cats and she could simply tell him and his littermates a stern “no” and they’d leave her cats alone, but he locks on and if the cats move or if they’re somewhere he didn’t expect he goes after them. He hasn’t injured them so far, but it’s only a matter of time at the rate we’re going. He knows if I’m close by or if he’s on a lead to not try anything, but he’ll jump a baby gate (not many doors in my house to separate them) to get at them.

Currently, among other things, I’m working   
\*\*1\*\*. disengaging and breaking the fixation before he starts to lock on and   
\*\*2\*\*. his impulse control with moving toys but only rewarding once he’s maintaining a sit/eye contact.

Is there anything else I could be doing to mitigate this issue? I know these things take time but like…dang, dude. TIA!