I make a tweak that works in backboardd, if I just respring after install it, it doesn't work, I have to restart the my iPhone entirely. Are there any other better ways need not restarting device?
You can execute this in your postinst script if you are installing your tweak as debian package (*.deb)
launchctl stop com.apple.backboardd
Backboard will restart automatically and cydia-substrate should be able to inject your tweak in it.