For step 3, after installing Matlab Runtime 2022b, it works! Now Brainstorm loads fine. Thanks for the suggestions
This is some great news!
Unfortunately, it's not a major surprise that newer versions of MacOS require the latest versions of the Matlab Runtime... The life span of compiled software on MacOS is usually very short compared with Windows.
I adjusted the Installation instructions to this new information: https://neuroimage.usc.edu/brainstorm/Installation#Requirements
I recompiled the latest version of Brainstorm on Matlab 2022b.
Please try downloading the latest package available on the Download page:
bst_bin_R2022b_221130.zip
I also recompiled the 2020a version with some fixes.
Please let me know how it goes.