My application test builds have been boring.  I had to change orcascr170 to orcascr190 in my build script, and then run the build script.  There have been no PB bugs to search for in the build process.

My build process is to create all my pbls from scratch, pull all the source from my Wizsource SCC system, load all the pbls, and then do the build.  All done via a call to a single build batch file.  All my applications build just like in 2017R3 and runs great.

i continue to develop in 2017R3 and and then build in both the 2017R3 and 2019R2 for testing.  Up until i am ready to convert the source code to 2019R2 when released.