It's not that easy. I've tried this on my server. You're not falling into the void because you clip through the ground, it's because of the time it takes for the chunks to load on your client. Even if someone else has the same chunks loaded on the server.
My old solution? I used to have a safe fall shaft that goes from bedrock up to near* build limit. I start by finding a spot to dig a 3x3 shaft to bedrock. I then place a 3x3 pad of hay at bedrock. In the center of the hay, I jump and place a frame under me at the same time. I repeat this until I have used ~230 frames. At the top I use the /sethome command. Once home is set, I remove the frames. When I hit /home, I only see the void and start falling. DO NOT MOVE while falling. I usually don't see the chunks load until right before I hit the hay. The time it takes to fall ~230 blocks is enough time for the chunks to load and land safely. I then have a separate custom command to teleport to my crafting room. It's ok to tp up there once the chunks are loaded. If you're not the admin or on a PVP server, you could dig a ramp or a separate ladder shaft to get back up to your base.
*DO NOT go past the build limit of 255 (I think). You'll get null errors galore. It was a pain to get out of.
Now, with dmustanger's server tools, I only have to wait ~10-15 seconds and hit /home again to get out of the void. Other server manager's force you to wait 1 minute. You'll have to set /home timeout to 0 in the config file. It is 1 minute by default IIRC.
Alloc has said that this will be fixed in A13.