That would still create an invalid xml file if you use xUnit output.
I use jenkins so the results should be readable from it too. Agree you can handle the xml file manually to make it valid but it looks like a lot of useless work compared to a single line in (windows) batch if you split the tests

for /f %%f in ('dir /b "Tests\*.exe"') do Tests\%%f -o %%f.xml,xml