Sounds like SuperCollider creates a new instance of the kick drum for every note, and doesn’t destroy them/free up resources until the sound has faded out completely.
With fast triggers, and a long decay time, notes will stack up until the CPU overloads.
The SuperCollider engine could be rewritten such that there’s only ever one instance of each drum sound, that’s re-triggered, rather than each trigger creating a new instance, while the previous one continues to play.
That way, the CPU load would remain constant, but some clicks might be introduced due to sudden volume changes.
I don’t know if this behaviour will be more or less like the way a real 808 sounds, but I don’t think either really mimics the real response of the original hardware.