Hi Alban,
you are right, two seperate commands and it works.
But how many mistakes will be made against this?
How long will it take before someone thinks to optimise the commands and put it together?
Every project also needs his own commands (some will use report aggregate and not report, or whatever). Thats the nice thing about the maven lifeycle, you can attach stuff to it that is project specific and run default maven commands.
Also, how long will it take me to explain why thats needed to all the teams?
The bottom line for me, is that something as basic as code coverage should run simple and be correct.
And it was very simple with the binary format, as we could just write to one single file. The xml reports overwrite each other if you try to write it to same location, it does not have an “append” function.
Sonar plugin also runs at the end of the maven build, which could also be an option for the xml report.
There are good options that make it as easy as ever.
I dont feel comfortable pushing workarounds to the entire company over something that I was hoping is basic in 2020 
kind regards,
Peter