Wordpress Plugin Customization [ woocommerce delivery Slots ]

Looking for someone who is really good at customising woocommerce or wordpress plugins. The person should be able to add a logic to the plugin : Woocommerce delivery slots. Link to the plugin : [login to view URL] He should be able to add an option in the plugin which would lockout a time slot before one hour of the time slot or any specified time. Eg : There is a slot at 9pm. People can use the slot till 8pm but cannot use it any further after 8pm i.e. the slot locks out automatically before an hour. PS: you should be able to change the time frame i.e 1 hour in the above eg. So you will have a to add an option on the plugin dashboard too.