I listened to Despecialized, and the echo is on the 5.1 recreation, the Stereo recreation, and the both of the laserdisc mixes.
Notably, it is not on the mono mix, which as I understand is what the special edition based most of its sounds on.
EDIT: As for what SSE used, if it’s similar to the 1.0 release, it uses the '93 laserdisc, best as I can tell.
I remember a mention in a thread somewhere around here that addressed this particular mix. The 2011 BD didnt have the distinct echo delay, but the GOUT does. I more or less wondering, what is the real mix and when was it changed?