ᐅ Is it advisable to consult a structural engineer even if not legally required?

Hello dear forum community,

Our building application has been submitted, and suddenly a new question arose for us – whether we need or want a review engineer / independent structural engineer?

Apparently, for our project (a detached single-family house without a basement and a pitched roof) here in Berlin, it is not required. However, the architect recommended it, as the review engineer acts as a quality control by closely monitoring the work of the different trades, and everyone apparently respects that.

I am a bit confused now because the description above sounds more like the role we had in mind for the independent construction supervision (quality control during construction).

So my questions are:

1) Does the review engineer only check the structural engineer’s documents, or do they also conduct quality inspections on the construction site from time to time?

2) If it is only the first, should we still commission the review engineer even if it is not required, or would that be an expense we could confidently save if we already hire an independent construction supervisor?

3) If the review engineer does visit the site regularly, would it be possible or sensible to assign the independent construction supervision to them as well?

I hope these are not silly questions. We are happy to pay for both services if it makes sense; I just want to make sure it applies to our situation and that we’re not wasting several thousand euros on the review engineer simply signing off on the structural engineer’s documents once...