I don't think there will be any big surprises happening in the final minutes of the transfer window.
Heidenheim against Dortmund is quite worth looking forward to because in terms of quality these two teams are not too different, especially since Heidenheim is a strong team when playing at home, of course Dortmund will have quite a difficult time in this match in my opinion.
Heidenheim has indeed drawn when the match took place at Dortmund's home ground, so it is very possible that Heidenheim will be stronger when playing the match at home against Dortmund. However, I don't think that Dortmund will experience too much difficulty when facing Heidenheim, because recently Dortmund has also started to get better and has also returned to the top four of the Bundesliga after being able to win at home when they hosted Bochum.