I’m a bit slow in reporting this. I saw the announcement on May 5th, and I downloaded and installed on that same date. This was for build 0184 of 42.3. This was followed a few days later by build 0229. And yesterday we saw build 0243.
I downloaded the install DVD for build 0184 from the download site. That site should have the current build during the testing phase. As of the time of this posting, you can find build 0243 there.
As usual, I downloaded with “aria2c”. I also downloaded the sha256 checksum file (I used “wget” for that download). I verified the gpg signature on the checksum file. And then I made sure that the downloaded iso matched the checksum.