This is something I've wanted to cover for a while now but not been able to due to not owning a Mac myself. Thankfully CandiceJoy on the ZDoom discord helped modify my instructions for using the Blood upscale pack to work on Macs. As it turns out running it on Raze temporarily works the same way as in Windows, but persistent installs are a bit different
1. Copy the autoload folder to a folder where you know the location (such as /Users/<username>) and rename it to bloodupscale
2. Open Raze's config file. Its name will be dependent on your computer name but it always ends in .ini (by default this is in /Users/<username>/Library/Preferences)
3. Add the following lines
[Blood.Blood.Autoload]
Path=/Users/<username>/bloodupscale/*
Raze can be downloaded here