It looks like there's a memory load somewhere in the game that gets purged between new games. My run got really laggy as I progressed, but when I went for New Game+, it ran just fine again. Using Chrome, if it makes any difference.
Rate of production of meat = drone production rate * (current drone count + queen production rate * (current queen count + nest production rate * (...)));
Just have this calculation run once whenever the player upgrades, then store the expected time for the meat to reach its desired value, having the timer count down based on that.
I haven't implemented a hard reset yet, but here's an export code from the very beginning of the game. For now, just import it if you want to reset: NnwwfDB8MHwwfDB8MHwwfDB8MHwwfDB8MHwwfDB8MHwwfDB8MHwwfDF8MXwxfHRydWV8ZmFsc2V8ZmFsc2V8MTUwOTczMjc1NzM3NXwwfDF8ZmFsc2V8ZmFsc2V8ZmFsc2V8MCwwLDAsMCwwLDAsMCwwLDAsMCwwLDAsMCwwLDAsMCwwLDAsMCwwLDAsMCwwLDAsMCwwLDAsMCwwLDAsMCwwfC0xLC0xLC0xLC0xLC0xLC0xLC0xLC0x|ZWZjYWQ5OGFhMjA0ODczMjhmNjhlOWVkMmYyMTA3MWM=
I haven't implemented a hard reset yet, but here's an export code from the very beginning of the game. For now, just import it if you want to reset: NnwwfDB8MHwwfDB8MHwwfDB8MHwwfDB8MHwwfDB8MHwwfDB8MHwwfDF8MXwxfHRydWV8ZmFsc2V8ZmFsc2V8MTUwOTczMjc1NzM3NXwwfDF8ZmFsc2V8ZmFsc2V8ZmFsc2V8MCwwLDAsMCwwLDAsMCwwLDAsMCwwLDAsMCwwLDAsMCwwLDAsMCwwLDAsMCwwLDAsMCwwLDAsMCwwLDAsMCwwfC0xLC0xLC0xLC0xLC0xLC0xLC0xLC0x|ZWZjYWQ5OGFhMjA0ODczMjhmNjhlOWVkMmYyMTA3MWM=