I have removed copyover and added hotboot before,
Personally, I would grab the latest version of swrfuss and use its hotboot.c and hotboot.h and follow Greven's instructions for adding hotboot.
You will want to remove the copyover and copyover_recover functtions.
I imagine Greven's hotboot snippet has not been modified on his site in months, I am however sure that his modified version is kept up to date in the swrfuss packages.
Also remember to include the Dlcym code in the appropriate places near execl if dynamic command support is installed.
If not using swfotefuss or another code modified by the smaugfuss project you may need too replace accept_neww with the fuss version.
I had problems with crashing immediately after a hotboot on my near stock copy of swrip with most smaugfuss fixes added.
Someone should remove the copyover in fote and add hotboot.
I might just do that if someone could make use of it, its the least I can do.