Make up Air System

I've purchased a new build and the builder won't let me increase the duct size from 6" to 8" because of negative air pressure. I decided that I'll probably do it after closing anyway because I'd like to have a range hood that is at least 700CFM and most range hoods with 700CFM+ require 8" ducting. Although the rangehood will have to ability to go up to 700 or 1000 CFM, it's highly unlikely that I'll run it at the maximum very frequently or for extended periods of time. I just want the option to be able to run it at the maximum for the odd time we're grilling a steak or something that might stink up the house. Has anyone ever experienced negative air pressure and/or installed a make up air system? I'm assuming most people have not but I wanted to confirm if this is something I need to consider if I were to go with a higher CFM range hood.

Here's a good article of negative air pressure and why installing a make up air system can improve air quality in the house.

https://www.pvhvac.com/blog/before-you- ... -read-this

On a separate note, we all know that we should probably open our windows once in a while to let "fresh air" into the house even during the Winter. Curious how frequently you guys do this and wondering how much this actually helps reduce negative air pressure.