After some round trips with the ngspice developers the feature i have requested has been implemented (in pre-master branch for now): a

.save

instruction placed inside a subcircuit will save the specified node in the raw file. This means, if i have an opamp with an internal

A

node and the opamp is placed 2 times as

X1

and

X2

in the main circuit, a

.save v(A)

inside the opamp subcircuit will cause

v(X1.A)

and

v(X2.A)

to be saved.