Is a Hennessy asym really a flatter lay?

[River Diver]

Would adding tie outs to the ENO DN (by stitching anchor points on the extra flaps) make much of a difference?

I am not sure because I have never tried that but, the HH does have a different shape.

[gordonfreeman]

Would adding tie outs to the ENO DN (by stitching anchor points on the extra flaps) make much of a difference?

Nope, it's a length issue not width.

[smitty.srs]

I have an HH Expedition side zip and a WL Snipe. I'm 6' or so and I find the HH a little confining. I'm a side sleeper as well and find that I can't sleep comfortably on my side in the HH, but can in the Snipe. I just can't get as flat in the HH as the Snipe. It is definitely a length thing.

I still prefer to sleep on my back in a hammock and am getting more used to it. In fact, the more I sleep on my back in the hammock the more I do on a mattress.