No, replacing your HVAC or control systems will not magically fix the engineering issues present in your home/building. You will have to compensate for poor design indefinitely unless you want to demolish and start over.
Oh fuck, improperly designed HVAC + changes made to a building that really fuck it up... There's no fixing that folks.
"This one room is always hot!" Well, there's no return, the door's always closed, and oh, someone replaced the door 20 years ago and now there's only a 1/4" gap between it and the floor. No, "turning up the fan speed" isn't going to fix it.
Because modern houses really don't give any thoughts about airflow or natural cooling. Heck, even getting the AC compressor installed on a side of the house where it doesn't get baked in the afternoon sun is too much to ask for.
Do you have any suggestions for those interested in learning about HVAC design principles? I'm currently far enough along in experience where I've discovered I know very little because of how complex each part of the systems can be. I've ran into so many questionable setups doing inspections but would love to be able to look at a unit's specs and follow the runs making sure nothing immediately eye-catching is going on.
I have similar experience with Electrical and Plumbing, 99% of the time it's common mistakes made by installers or not following code properly. HVAC is near impossible to fully grasp because of the code terminology and arguments over best practices. Even something as simple as a range hood gets people confused because of the exhaust type versus code requirements.