There is a mode on Kurzweil sequencers which allows whatever pattern you entered initially to be extended automatically while doing an overdub. For example say you entered a 4 bar drum measure and then are doing an overdub with a bass line or piano but the overdub goes longer than 4 bars, the drum pattern will automatically be extended by however long you play the overdub for.
Might be a nice option to have as a record mode in the S2400.