On the website there is a changelog for BIML 2020 R1. However, the BIML I download from is always the 2019 version.
How do I download the 2020R2 release?
Release notes: https://docs.varigence.com/bimlexpress/release-notes/BimlExpress-2020.1
Download page: https://www.varigence.com/BimlExpress (gives you build 5.0.64108.0 which is 2019)
After my last meeting with Varigence, there is no indication that they will throw any resources into releasing a newer version of BIMLExpress.
Of course, they don't make any money from BIMLExpress, but with a functional product, new developers will come and find out how nice bimlscripts are. But now they have obviously chosen to kill every new developer's opportunity to fall in love with bimlscripts.