Free-Form Railings Flow Problem

HI All ,

I want to build a almost free-form H-beam railings.

I have a curve (crv 1) on the top of H-beam railing as rail 1 , and Flow to create a new curve (crv 2) which is in order to use sweep2 as rail 2.

But the output curve(crv 2) of Flow has a little twist on the turn of railing, so the output of sweep2 also has a twist. (61.3 KB)

Have any solution to deal with the output of Flow ?
Or maybe have some better way to build the model.

Thread was split because the author deemed it to be a separate issue about flow component