Hi, I have a workflow question.
I see that in a portfolio, one can add several deposit and securities accounts (and the tables for them have really many rows).
So my question is, whether should I add multiple accounts from different brokers in one portfolio?
Is it considered a best practice? Especially, if some things are in euros and other in other currencies.
Danke im Voraus! 
This is the main reason why Portfolio Performance exist.
No, this is common practice. As PP has a reporting currency and the ability to handle foreign currencies.
You may want to look up: Getting started - Portfolio Performance Manual
OK, thanks. I have realized that the docs in German have a little bit more information about this: they say explicitly about multiple accounts in one portfolio, at least on the “Intro (de) / About (en)” page.
I am not sure that I understand now how then I can assess the correctness of the information that I have entered (whether it matches the broker info).
Should I check the correctness only on the Securities page (whether I have the same quantities as the corresponding broker account states)?
There is an English explanation as well:
We are still working on the documentation.
The docu includes a section on how you can start best.
When you have all the data from your broker, you either add the buys and sell including cash accounts, or you work with inbound delivery. Both are explained in the manual.