These are some notable (at least I consider them as such) personnel decisions since the end of the regular season (I mostly focused on German players):
(The latest additions are in red)
Augsburg
In: Fabrizio Pilu, Enrico Henriquez-Morales, Tim Wohlgemuth
Staying: Florian Elias, Moritz Elias, Leon van der Linde, Luca Tosto
Berlin
Out: Michael Bartuli, Linus Vieillard
Staying: Jonas Stettmer, Eric Hördler, Ty Ronning
Bremerhaven
In: Leon Hungerecker, Nico Krämmer, Bennet Roßmy
Out: Maximilian Franzreb, Cedric Schiemenz
Düsseldorf
Out: Alexander Ehl, Bennet Roßmy
Frankfurt
In: Tommy Pasanen, Fabio Kose, Timo Kose, Noah Dunham
Out: Dominik Bokk, Julian Napravnik
Staying: Daniel Wirt
Ingolstadt
Out: Noah Dunham, Enrico Henriquez-Morales, Fabio Wagner
Iserlohn
In: Bence Farkas, Julian Napravnik, Daniel Neumann
Out: Michael Dal Colle, Jake Virtanen
Staying: Hendrik Hane, Taro Jentzsch, Manuel Alberg
Köln
Out: Niklas Lunemann, Mirko Pantkowski, Edwin Tropmann, Justin Schütz, Tim Wohlgemuth, Elias Lindner, Hakon Hänelt
Staying: Tobias Ancicka, Jan Luca Sennhenn, Maximilian Glötzl, Robin van Calster, Maximilian Kammerer, Kevin Niedenz, Parker Tuomie, Marco Münzenberger, Gregor McLeod
Mannheim
In: Maximilian Franzreb, Alexander Ehl
Out: Daniel Fischbuch, Stefan Loibl, Fabrizio Pilu, Arno Tiefensee, Paul Mayer
München
In: Philipp Krening, Ryan Murphy, Luis Schinko, Phillip Sinn, Fabio Wagner
Out: Andreas Eder, Sten Fischer, Nico Krämmer, Nick Maul, Filip Varejcka, Jakob Weber
Nürnberg
In: Timo Bakos, Jakob Weber
Out: Leon Hungerecker, Lukas Ribarik
Staying: Julius Karrer, Justus Böttner
Schwenningen
Out: Daniel Neumann
Staying: Alexander Karachun, Tylor Spink, Tyson Spink, Sebastian Uvira
Straubing
In: Stefan Loibl
Out: Joshua Samanski
Staying: Florian Bugl
Wolfsburg
In: Leo Hafenrichter, Matt Choupani, Til Raab
Out: Luis Schinko
Very sad. RIP Tobi