Hi Psygorn, for the tiny edges it would be good to get rid of them using Merge.

re:
"There are tiny edges that were not selected by Blend"

Blend does not itself select edges, to make the blend include the tiny edge you would need to also select those tiny edges before doing the blend so they are included. But getting rid of them would be good too.

re: "And Blend makes it warped"

Blend is deciding to reverse one of the edges, you can override that by clicking on the edge while in the blend options, it will then flip to the direction you need.

But Blend might not be the best here anyway, it will make a surface that is smooth to the other surfaces but the "side edges" will not be smooth to each other.

You would get smooth side edges if the edges being blended were also natural edges of the underlying surface like if they were the end of a loft or sweep surface instead of being a trim curve that's on a larger underlying surface.

- Michael