Entry - The wheel mount side panel recedes towards the foot rest, this is intentional, reason - being able to slide your feet first for easier entry. The wheel mount itself has a simple articulating design, but it's still in testing phase.
Padding - The seat itself is very comfortable even without padding (maybe it's just me though
), but of course I'll be suggesting options along with a guide. You can find foam padding in local fabric and hardware stores. I've seen a few, but haven't any of them just yet.
Leg/Thigh Support - The comfort level is good with the design. The leg and thighs are greatly supported. The issue would be the fit - the width of the core of the rig where the legs enter to be exact.
Buttkicker - Should be very easy to implement! I have some Aura Bass shakers that I used in my previous rig that are laying stagnant in my storage. I'll have them dusted off once I finish the rig.
Shifter Mounts - Very easy to implement with simple articulating arm design (Aluminum extrusions/tubing)
Design - I am planning to release multiple variants of the DIY guide; Comfort, Realistic, Functional, or Combination. Factored in are wheel and pedal compatibilities also.