This worked for me by editing the /etc/init.d script:
procd_set_param limits core="unlimited"
example procd script:
#!/bin/sh /etc/rc.common
START=90
STOP=10
# SERVICE_DAEMONIZE=1
# SERVICE_WRITE_PID=1
USE_PROCD=1
start_service() {
procd_open_instance
procd_set_param command /usr/bin/myprogram
procd_set_param respawn
procd_set_param term_timeout 60
procd_set_param pidfile /var/run/myprogram.pid # write a pid file on instance start and remove it on stop
procd_set_param limits core="unlimited"
procd_close_instance
}