Thanks for the clarification.
Does the same apply to character x character interaction? For example, I'm on BL route, could I still trigger the C support post timeskip
A. Between recruited characters, each from a different houses (other than your own house) e.g. Ferdinand(BE) x Marianne(GD)
B. Between recruited characters both from the same house e.g. Ferdinand x Dorothea
C. Between a recruited character and a BL student eg. Ferdinand x Mercedes