You will have to contact Woocommerce about that. It's Woo's fault. Not the ALDS plugin's. As has been discussed in many places already. Even in the post just above yours.I hope in the future we can use alidropship woo without the lack of high cpu usage
The good news is that Woocommerce is aware of the problem and perhaps in the future it will be fixed. This problem does not just affect the ALDS plugin ... but anyone who uses Woo.