71 Duster 360 turbo build

It doesn't seem like converter slip to me. There's a big rpm drop on the 2-3 shift for sure
View attachment 1716318569

At what point is it not big enough of a drop? With zero slip the 2-3 shift should drop from 6400-4500rpm. So the converter is currently flashing(?) 1000rpm higher than that. Is this acceptable?