Thank you so much Prof. Pfeifer for your answer. I have some additional questions if you don’t mind:

Do we mean by append here, log substitution similar to exp substitution (instead of log_y = log_y - log_y_ss)? and in what way is it easier?

After the exp or log substitution, should we let stoch_simul in its default settings?

In case we let the model in its non-linear form without any form of substitution, will invoking the loglinear option in stoch_simul be enough to get irfs in term of percentage deviations? if so, in what way the substitution techniques are better?