How to create two surfaces using these curves and joining them together at the end?

I want to test how can I joint multiple surfaces while keeping tangency (G1 or G2). Please guide me. This can be useful in complex models.
1.3dm (243.1 KB)

MatchSrf to adjust surfaces so that the edges match as desired. To match to just part of an edge use the “Match edges by nearest points” option and/or use Subcrv when selecting the second edge.

Join to join two surfaces into a polysurface. In some cases you can use MergeSrf to merge two surfaces into a single surface if the surface match along entire edges. However it is best to only merge the usual degree 3 surfaces if there is G2 continuity between them, or if G2 continuity is desired.