Even with the maximum "lifted" offset spindles, the Timbren suspension does not have a lot of travel. As a Jeeper, I'm used to seeing a lot more travel - BUT the whole trailer is pretty light, moves easily, so the trailer suspension does not really need so much independent travel. A Jeep is a lot heavier and the suspension may need to droop a wheel into a hole, or compress over a rock, which requires more suspension travel than a lightweight trailer does.
That said, the Timbren rides WAY smoother than my old leaf springs ever did. And has more travel too. But, yeah, only about 2.5 inches of travel.
Have you actually checked how much travel a leaf spring allows? Not as much as you might think. My old leaf spring suspension only had about about 1 inch of travel, as evidenced by the shiny area of the shock absorber.
Side note: Remember to plan for 10% tongue weight (or a little more, but not less than 10%). See this great demo of how tongue weight really matters.
https://www.youtube.com/watch?v=w9Dgxe584SsA couple of things to watch out for:I did everything I could to try & get a great installation. That included having it installed by a professional boat trailer builder, and having him weld on a strip of 5" x 1/4" steel all the way from the front to the back, along the underside of the trailer. One on each side. Attached the Timbren suspension to that, so it could not twist in/out. Really made the frame a lot stronger (I've torn the frame before). Also added the cross bar (not an axle, but I don't have anything against axles) to brace the 2 wheels against each other for strength. Timbren says that bar is optional, but recommended for us 4x4 guys.
Welp, we still have a minor issue with the tires being farther apart at the bottom than at the top. Which is causing faster wear on the inside edges of the trailer tires. Now that the weather is nice, I need to climb under there & see what else I can do about that. Shims, maybe.