I have a few thoughts on this subject but remember that anything said here is just one persons opinion.
First: Dragging the headsail across the inner stay while tacking has never caused a chafe issue for me. I've been doing it for 35 years. On occasion I must go forward and help a headsail pass through but I'm sure the time spent doing this is far less than the time it would take to set-up or remove a detachable inner stay.
Kern used to say "Luff length is performance. Foot length is crew abuse" This is, of course, referring to going to weather. With the wind forward of the beam the boat will perform better with more Luff length and less foot length. That is, two sails instead of one. The Luffs are helping to "pull" you forward. This requires about ten pages of explanation though because there are other factors involved. The extra "pull" can be negated by a poor slot. That is a slot that is choking down the air flow too much. The picture of Soletro, though a nice picture, is showing a choked slot. The boat would be faster with a smaller staysail, or smaller headsail, and/or different sheeting angles.
As the boat moves toward a beam reach, then "square footage" comes more into play and the "pull " of the Luffs airfoil becomes less. At some point, as you approach a broad reach, then extra luff is not going to help in performance. Square footage has taken over as the primary mover. Once on a run, then square footage is just about everything. ("just about"), but of course that square footage must be projected to the wind, as on a pole.
The Westsail 32 and 28 are low aspect ratio rigs compared to anything remotely modern. This is not really a negative, but it is part of the explanation as to why the boats sail better with the two forward sails as opposed to just one big one. (notice the small picture up by my name) If sailed like a sloop when going to weather, there is too much space for the air to maintain a nice flow through the whole area. The second sail just helps that air move along nicely and cleanly and making sure it hits the Mainsail correctly.
Certainly a big genoa can and has been used free flying with some effectiveness. It is then a big heavy drifter. I think a more proper drifter using 3/4oz to 2.2oz material is more effective 95% of the time. I consider such a drifter a good investment for the Westsail. Locally, here on the river, A typical sail is upwind with the Working jib and Staysail, and then back home with the drifter.
At any rate, get out there and sail. Plan on being out on New Years Day. It is tradition.