Sorry that my problem description was so unclear! Thanks for your new solutions I learned a lot about grasshopper with them.
I try to explain my task/my problem and the difference between lofting and networksrf function with the help of many screenshot and only with Rhino without grasshopper. I hope things get more clear.
01.png I just baked your surfaces and then closed grasshopper.
02.png I extrated two edges from the surface in the middle and deleted the surface in the middle. (those to extracted edges are your blends and those curves are tangential to the outer surfaces)
03.png Now I use the networksrf command. (“Kurven im Netzwerk auswählen” is the German translation)
04.png Now I chose the two edges of those two surfaces and the two curves
05.png I press enter and networksurface function “asks” me about the preferences for each edge. For edge C and A I take tangential.
This step is what I want to reproduce in grasshopper. If I us the grasshopper-network-surface-tool and take the edges of both surfaces as u-direction-input and the curves as v-direction-input the created surface is never tangetial in the connection area at position C and A .
06.png I get a surface which is tangetial at position C and A without any additional input curves like the 50 blending curves you took in your last solution.
The powerful difference between lofting and networksrf in my opinion is, that with the lofting command will never get the same surface with tangetiality if I have only those four curves (or more precise two edges and two curves) as an input. Plus, if at the left was a third surface which was tangential to the other two I could also use an edge at position B and tell it to be tangential.
If I reproduce the same task with grasshopper I dont get the tangentiality to both surfaces. Is it impossible to do so with grasshopper with only those four curves as input? If yes your solution is the perfect workaround.
07.png Here you can see again the area where I have tangentiality.