To get the visual editor to generate nice code, ensure any block templates you create have
"format": "{{_|_=_}}\n" (as inline but with trailing newline)
or "format": "{{_\n|_=_\n}}\n" (improved version of block)
in the TemplateData—see docs.
This is unfortunately necessary to do on each individual template since the named aliases are hardcoded.
(Getting the generated invocation to not be in sentence case is a lost cause. It seems to honour what was entered manually though.)