Mv Flat Shipping Add-On

Another question… are there any existing add-on or has anyone created one that will bypass all of the individual shipping charges per vendor during checkout, and only charge one final shipping fee for the entire order? This is a must for companies that is doing fulfilment for their vendors. Any info would be greatly appreciated, thanks!

I actually have an old shipping addon made for v3 that will do this (only charging the fee from the first vendor listed, and auto null the other ones during checkout)… can any developer here help me convert the add-on for v4? please email me at thank you!