the refill timer is exactly as you said ... if set to 120 and refill amount is 10 . then every 2min it will add 10 items to stack till max stock is reached ... but that readd is dependent on server stack size .... so with 100000 max stock ... and scrap stacks to 1000 at some point plugin in that regard will stop working as there is only like what 32 slots in vending machine and that means refills will stop after 32000 and not mentioning the fact that in that it cant accept the incoming item due to no space