Thanks for the reminder @esmi and @damiaan. Anyway, again not sure if this is appropriate here (kindly delete please if unsuitable) but while I was trying to figure out a solution to this, I had a look at another plugin called APG Weight and Postcode/State/Country Shipping and tried on another site I am working on. I was trying to do the exact same thing and the closest I could get was getting a notification once the order was above my set max weight limit saying:
"There doesn‘t seem to be any available shipping methods. Please double check your address, or contact us if you need any help."
Addendum: This notification is what customers see on checkout.
I think this will do for now, and the closest I could get anyway rather than having to have the same shipping rate charged to customers for the maximum weight and the overlimit.
Hope this is of any help.