I've been looking at the pictures you and TeeDee posted, and I get the impression that the ridgeline is mighty high relative to the prone occupant. Doesn't look like lying on your back you can reach up and touch it.
The main role of the ridgeline is to control the flatness; given the height of the spreader bars above the floor of the hammock, the method of attaching the ridgeline to the suspension rings will always make that very high. This does not have to be the line accessable to the occupant.
It seems to me that you could run a separate utility line from spreader bar to spreader bar, for hanging things you want near at hand in the hammock, and this could be a place where you thread your underquilt control line. Might also be a place to support the top of the bugnet, rather than also running that all the way up to the flatness control line.
Depending on the spreader bars, you could try to make this lower line the flatness control line as well, although centering could be an issue. A finesse to this would be to have two flatness control lines, extending on each side from the endpoints of the spreader bars. This would not put undo force on poles, but would make getting in and out over the side a bit trickier.
just some thoughts,