sKetchyy

The first issue I see here is a noticeable CPU bottleneck. The 2700 can't properly feed a 2080 on 1080p and the 2080 probably enters lower power states since it's not properly utilized. Switching from lower to higher power states causes stutters too.
There are three ways to mitigate this; increasing the details to maximum (slightly decreases the bottleneck), upgrading the CPU or upgrading to a 1440p or 4K monitor.
 
The second issue I see here is XMP 3200 on a Zen+. That's nearly impossible to achieve, those CPU-s are hard to get above 3000 working stable unless the memory is Hynx CJR or Samsung B-die and the CPU a golden sample. Try using second XMP profile (should be 2933).
 
Does the board have the latest Bios?
Did you install the chipset drivers available on AMD-s website? Or the old ones from Asus?

You need to setup the following before the work
- Scope of work (What is covered by you, what they expect)
- Number of hours project will take complete
- Use the calculation to figure out the fee
- Make sure to have some mark up there for any materials you may need
- Call backs should be calculated before hand. So hours of project is: Pre-migration, migration, after migration follow up. This way your time is covered everywhere.
- If after the project, you didn't use up the time alloted, you can mention you can help with some other IT project and move the hours to thatt project instead.
 
This is very rough advice, but should help you go in the right direction.

We live in a world where GSYNC technology is supported on Freesync monitors so again, thought it worth an ask just in case.

you will have to get a brand new motherboard different sockets 

Fantastic thanks for the reply's! I shall take your advice and go ahead and get the Dell monitor  

With Freesync at least, it's recommended to use frame limit slightly below VSYNC and enable VSYNC as well.
In case that helps  
 
AMD settings let you create a profile for each game, if I remember correctly that's the case for Nvidia as well, so maybe try setting limits for each game separately in the control panel, they may have a built-in solution for popular games that don't follow the general settings for Gsync.

I’m using an i5 and it does really only seem to be Twitch that totally kills it. I’ve tried what you suggested and hopefully it works itself out! 

Don't make me use this: