I don't know if you mean screws in the Leviton plug you were buying [bad], or the amplifier boards [good].
(Just for safety, I want to be 100% sure there is no possible confusion between the AC and DC sides of the power supply).
My writing is a bit convoluted sometimes. This should explain my plan better:
Take my current setup:
Remove the existing wall wort PSU completely and remove the set of positive and negative wires that were going from the PSU into the master end of the terminal block. Take my Leviton out of the outlet, and remove the negative wire from the grounding screw. Cut off the plug end of this (
https://www.amazon.com/dp/B09CKTJ96N?ref=ppx_yo2ov_dt_b_product_details&th=1) and replace it with the Leviton by wiring the positive and negative wires from the lead wires that came with the above linked PSU to the positive and negative screws in the Leviton. On the other end of the leads, connect the positive wire to the terminal blocks in the same fashion that I use now, which gets sent to the power positive inputs of both amp boards. Do the same with the negative lead, but use a second terminal block to make a second split, and from the output of that negative, connect another wire and connect it to the ground screw of the Leviton. Then, plug the Leviton into an outlet. I already have a second terminal block which I use for the current negative split. Please see the attached which shows the setup without one set of wires connected. Currently, I use a second wire to go from positive to positive between terminal blocks, before getting the other two positive wires to the power positive inputs of the amp boards.
I thought this would work, as I'm just replacing a PSU end negative wire going into a separate plug's ground screw, with a different PSU's negative end going into its plug's ground screw; the only difference is that in this plug I'll already have positive and negative wired to the appropriate screws.
So, assuming I explained my plan clearly enough, is the workable and safe?
See the terminal block on the right. I'd connect power positive to the red slot on the right, and then on one of the left red slots, connect a short wire to one red slot on the other terminal block. This gets to the power positive inputs of both amps. On the terminal block on the right, I'd connect power negative to the blue slot, then on one of the left blue slots, connect another short wire to the blue slot of the other terminal block. This gets to the power negative inputs of both amps. On the second blue slot on the left side of the terminal block on the right, I'd connect another wire, and then connect the other end to the ground screw of the Leviton, which would already have the positive wire of its own lead connected to the positive screw, and the negative wire of its own lead to the negative screw.
I think I described my plan clearly enough now to get a definitive answer. Will this work and be safe? I have no problem keeping my existing setup; I just find it a little odd to have a second, dedicated plug just for ground, and if my proposed solution works, I'd prefer to use it.