It would be a great feature, as shipping is often calculated by weight as opposed to price. I was trying to modify the plugin php - without modifying the front-end - by using the percentage field I thought I could make it work like this:
At line 59:
$rates[$k]->shipping_price = round($rate->shipping_price + $price*$rate->shipping_params->shipping_percentage/100,$currencyClass->getRounding($rate->shipping_currency_id));
I tried substituting this line, but I'm not sure of the variables, and it doesn't work.
$rates[$k]->shipping_price = round($rate->shipping_price + $rate->shipping_weight*$rate->shipping_params->shipping_percentage,$currencyClass->getRounding($rate->shipping_currency_id));
Do you have any suggestions here? Thanks.