A lot of trikes I looked at had the option of horizontal bars. It's just a piece that mounts to the vertical and can be removed if you don't like it.
https://i0.wp.com/tridenttrikes.com/...ize=768%2C1024 On my df bike, I had to get a pro setup as I have one knee that allows a 1cm happy zone and if I'm out of it, that knee hurts. I woke this morning and that knee is hurting so I know something isn't set quite right. I did the measure the boom with just a slight bend thing but with such a tight tolerance for my left leg, I guess I will have to spend some time (and pain) tweaking it by tiny increments to get it right. But - with a big bucket type seat I don't know that every time I sit down I will be in the exact same position. There was only one option with the df bike. If I am sliding forward is the seat angle too upright or too low? My legs aren't strong enough to keep me from moving forward on the seat, they just get more of a bend. I've got the pedals set under the lower part of the ball of my foot - is that still right for a recumbent or should it be more towards the arch (platform pedals with straps here)? Also, I'm not a very big person and I feel like there's a LOT of width to the seat so I could easily be sitting slightly more to one side than the other. I feel like I need a seat belt, lol.
I probably need to tighten the straps on the seat - I bet they loosen the most in the first few rides, and maybe that will help with suspension. It's not unpleasant, just different in what I am used to there. I usually prefer my tires to be inflated close to max.