So I meant to factory reset my Mac a while ago and decided to do it early last week. When I did I downloaded and installed the 14 day trial for Parallels and have been spending about a week trying to get things to work. I should mention I am not tech savvy in any way, but can follow online instructions.
So the first thing I did was make sure I had enough disk space for another operating system, which I did due to factory reset. (I backed up my sim saves and mods on an external hard drive before doing the reset)
Then I installed parallels, which does not come with all the necessary framework and c++ visual software so I found a tutorial and installed the proper framework files for Origin to even let me install it.
Once I was able to get origin installed, I had to download the sims 4 without any packs, just the game by itself, as parallels can crash and once restarted the game isn't finished then it tries to download packs, which obviously doesn't work. So I download my game, and all the packs I have (all expansions, most GPS, and almost all SPs) and made sure parallels would open sims 4 and run my game. Cas worked and gameplay worked (not any faster then it just being on my Mac considering the headaches to install everything literally took me 3 days of troubleshooting)
Once I knew sims 4 was running, I followed a different online tutorial on how to install Reshade.
It works. I am using reshade on my MacBook Pro 15" 2013. It's a pain and a hell of a learning curve, definitely not as easy and Lex buddy made it out to be, but with parallels it's possible.
Major downside to all of this is parallels is a $100 program with a 14 day free trial only. So while this is awesome and I am getting it to work I doubt I will bite the bullet and buy the program. I can't justify how much parallels is just to use reshade.
Hope this helps someone.