Yes I wrote in first part how to copy vector over:
math part:
Normalize second portal vector,
Get length of player velocity vector in first portal
multiply length by normalized vector from second portal, put it into result vector variable
physics part:
after player is in new portal place, stop pawn, (there may be node to do this), or set velocity to 0.
rotate it correctly
add impulse ( result vector variable)
And watch for mixing local vector space with world vectors. use one of them do not mix both without adjusting.