Connecting 'vacuum amplifier' causes hesitation off idle

See my new post on EGR
What new post on EGR? I'm not seeing one in your recent history. Maybe go ahead and link to it, eh?

I found a workaround

Anything like the EGR portion (toward the bottom) of this?

Slant-sixers might also want to put on the updated transducer-type EGR valve, EGV-490, which does a better job matching EGR flow to engine speed/load, thus cleaning up some of the driveability faults the previous-type EGR valves could cause.