iATKOS Inside: GPU update and High Sierra Open Core install doubts

GPU update and High Sierra Open Core install doubts

Hi there, after reading almost every guide on the sidebar I have a few questions:

My current setup is running the latest version of High Sierra. This is my main work computer and it has been working great for the last 4 years. A few of the apps I use to work are starting to no longer work on High Sierra, which got me thinking about finally updating my current GPU so that I can upgrade to Catalina (I’m currently using a GTX 1070)

First questions - GPU related:

Should I wait until the end of the year to buy a new $350 - $400 AMD GPU?
Should I just buy an RX 580 8Gb and call it a day?

If I buy a new compatible GPU I would need to do a clean install of Catalina, and as per this subreddit recommendation, I’m looking forward to doing an Open Core install but I’m currently overwhelmed by all the information available. I’ve been reading the Open Core desktop guide, Fixing CFG Lock, Getting started with ACPI, SSDTTime, USBMap, USB Mapping guide, and I just don’t know where to start and what to do first.

Now, a few questions about my current High Sierra install:

Should I just keep using it until all of the apps I need no longer work?
Should I try following the OpenCore Vanilla guide and do a clean High Sierra install? (I have a spare NVMe drive where I can do all the testing)
Bonus: If I do a clean Open Core vanilla install, would it be worth it? (Even if I’m using High Sierra)