Hello! This is my first posting here. I haven't bought any BlackIce Mx yet, but I am very close 
I have installed Yosys etc. on macOS 10.13.6 (High Sierra), see install logs etc. at [1].
MacOS High Sierra accepts 32-bit older executables. MacOS Catalina (10.15) will reject all 32-bit code after having issued future obsoletion warnings for ages. However, I assume that the Yosys etc. downloads (are they scripts only? I see some are Python) and the make builds that the installs did, resulted in something purely 64-bit? If not I will be lost when I upgrade to Catalina (two revisions "up"). (And if I had bought an Mx it would be of value equal to resale.)
(By the way, I really like this forum sw!)