It seems like when I ride over bumpy ground, it helps to stand up to absorb the bumps. It seems like a good suspension would help achieve this while seated.
There is an old saying:" a bad tradesman blames his tools."
Being a beginner I struggle with all the same issues and constantly think about ways to make the uni better. Being a gadgety kind of person also helps. 
I’ve actually come to realize that if you modify the uni too much you compromise the elegance and simplicity of it. There is something noble about using just your body and a wheel to accomplish what others can hardly fathom.
Having said that, I plan to build my own 29" suspension uni with a CVT hub and disc brakes for easy XC and the road. One day… 
Was that just because nobody made unicycle frames for 26" wheels? There were plenty of 26x2.3" tyres around in 1991 (give or take a year) when I had my first mountain bike (rigid fork so big tyres were very useful).
I don’t know what the obsession is with unicyclists and 24" wheels - silly size. I wonder why it became so popular.
Rob
Well I know I would sure appreciate suspension on my 29er because I permanently commute on it as I live in a bicyclist community. Riding in the dark, I often hit baby fallen coconuts or an unexpected bump in the road that causes a UPD. In the daytime this doesn’t happen because I can anticipate it, but I think suspension would help me to take these bumps better without anticipation. I also think it would just be more comfortable on bumpy ground.
Sounds like you need a headlight.
Well I have one, but I have an eye condition that cause me to see poorly at night. I have no peripheral vision in poor lighting.
This has been discussed in several threads over the years. The most thorough discussion and a few viable full suspention designs were in the fallowing thread. I don’t believe any of the newish designs in there have been ever built.
http://unicyclist.com/forums/showthread.php?t=32510&highlight=suspension