I think I may have found my first #Brompton-only train route that is actually tangibly useful to me. I have not tested it yet though.
#RB75 #DarmstadtNord XX:54 → #GroßGerau YY:25
~5min cycling #GroßGerau → #GroßGerauDornberg (pictured below)
#RE70 #GroßGerauDornberg YY:34 → #MannheimWaldhof ZZ:12
And then cycle to the #RaumZeitLabor in ~12min according to #brouter.
The way back in the night would be more interesting but it's strictly worse than the normal route via #Weinheim unfortunately.