> I noticed that I can't model all possible connections, e.g., A, B, and C I can only model 3 connections
> because of the n(n-1)/2 formula.
The underlying mechanisms and restrictions are the same for SEM regardless you use 1dSVAR or 1dSEM.
> If I want to check all possible connections, would you suggest doing something like A=>B A=>C, B=>A B=>C,
> and C=>A C=B and then use that to get like an overall summary of all the connections.
No, that would not work because SEM mainly is used for model validation. Try focusing on the lagged effects with 1dSVAR, which would give you the estimates of all possible connections among the lagged (instead of instantaneous) effects.
Gang