These are just buttons, IMO never used by Freikorps, even if the design resembles somehow the Freikorps insignia you mentioned. But, its not the same. The stag is far more elaborate and the Eagle is holding nothing in his hands.
I doubt a small insignia like the oak leave collar tabs would have served the purpose to distinct the own men in combat. Whats for sure was used for this purpose it the swastika worn by Marinebrigade Loewenfeld onto the left side of the helmet during the Red Ruhr Uprising. But it was cast-off very quick, because it did not succeed for the purpose of distinction.
So, from this, its to assume the arrow worn by Jäger-Battalion 37 (Roßbach) at front and side of the helmet, served the same purpose. Klietmann suggests this in his work on Roßbach.
And also the white armbands worn in late 1918 and early 1919 in Berlin an Munich, might have served this purpose. The "Reds" wore red armbands at this time. During the Munich soviet Republic and the Uprising in Wilhelmshaven.
Out of:
https://www.armeemuseum.de/images/publikationen/2018_Katalog_Friedensbeginn_online.pdf
Perhaps also the SSOS armband served the distinct purpose. It was widely worn by the Selbstschutz, but seems to have been not mandatory, because Klietmann mentioned for the Schwarze-Schar Bergerhoff they did not wore it.
The small insignia, like the oak leaves collar were IMO mostly worn because of pride, see this period ad for the Landesjägerkorps. Its mentioning the oak leaves collar and that they are troops under the command of Noske.