Time to continue with this story.
Now it was truss rod installation time. I opted for a vintage style, straight/tilted channels with a maple fill strip for the three guitars.
I have been using this simple TRs with good success. This is the TR style used in classic Gibsons up to the early 60s. This is a straight rod in a slighly oblique channel that is 1/8" shallower at the headstock. It needs to run fairly close to the back of the neck to be effective, and this is why Gibson changed to the curved ones when they went for thinner necks in the 60s.
Frankly, if I were to make any changes I might go for the curved ones, but it is unlikely I will use the two way TRs for the foreseeable future. I like the idea of less steel and more wood on the neck, and in my experience, with careful neck construction and stable wood there’s no real need for a two way TR.