I would say, you likely should be a happy camper, your channel has out grown your script.

this command well have overflowed

hadd -m sbot floodprosnicks $addtok($hget(sbot,floodprosnicks),$nick,44)

For two reasons,
One u never clear out anyone who QUITS and never returns
Two it can only hold around 950 characters

try in ON *:QUIT:{
hadd -mu3600 sbot Quitnick. $+ $nick $true

then in ON @*:JOIN:#:{
if ($hget(sbot,Quitnick. $+ $nick) == $true) { hadd -mu60 sbot Quitnick. $+ $nick $true | return }

You dont want to delete the Quitnick.<nick> flag for maybe 60 seconds more as the same nick maybe joining other channels also, 60 seconds might be more than you need but isnt excessivly long.