charge shipping for the most expensive shipping class

I defined two shipping classes:
– “heavy products”
– “light products”

For the “heavy products” shipping class I defined this weight based rate: 100|70|P1
For the “light products” shipping class I defined this weight based rate: 2|20|P1

If I have two products in the cart:
– Product1 belonging to the “heavy products” shipping class
– Product2 belonging to the “light products” shipping class
on the checkout page the customer will be allowed to chose between the two shipping rates: the rate for the “heavy products” shipping class, and the rate for the “light products” shipping class. This isn’t what I was expecting.

What I obviously need is to automatically charge shipping for the most expensive shipping class: the “heavy products” shipping class.

How could this be done?

Thank you

https://wordpress.org/plugins/woocommerce-apg-weight-and-postcodestatecountry-shipping/