You need to demonstrate real substance (such as actually managing/working from there e.g in your case Leipzig ) . If you can't prove real substance they will just shift it back to berlin and you could be also held liable for tax evasion (if there is a lower gewerbehebel )

It's perfectly fine if they - or you - shift it back to Berlin… after you're done with all the initial setup.

But also, yes, this is one of the reasons you can hire lawyer's offices to do this, they know how to spin it such that they're regarded as administrating the company in their location (which is arguably true at that point).

And just to note, there's the concept of "field offices" (Betriebsstätte) which would need to be set up. That does still involve Berlin bureaucracy, but only for a Gewerbeanmeldung.

(Really: ask a lawyer. I hope nobody is taking legal advice from a HN thread.)