There are no beta builds of Electrum, only the nightly one on the master branch which DireWolfM14 already pointed out.
It does appear that the site linked to by the OP auto-compiles binaries every time there's a new contrib. The Electrum master includes a
.cirrus.yml file, which defines the docker container that builds the binaries. You learn something new everyday.
Nevertheless, the skeptical cynic in me prefers to build the binaries myself.
@BoaTingacCident
Sorry I forgot about this thread, but here's the thread where I posted instructions on how to compile the binaries yourself:
https://bitcointalk.org/index.php?topic=5224252.0And some more reading material:
https://bitcointalk.org/index.php?topic=5221146.0https://bitcointalk.org/index.php?topic=5222986.0