Template:Convert/LoffAonSonNa
{{convert/outadj{{{?}}}|{{convert/round{{{?}}}|{{{1}}}|{{{2}}}/{{{b}}}|{{{3}}}|{{{4}}}|{{{j}}}}}||{{{n}}}|}}
Template:Convert/LoffAonSonNa displays a single output amount, for adj=on, when the output unit might not have a symbol {u}, as when a non-abbreviated (Na) unit.
If {u} does not exist, then "-{h}" (or "-{n}") is displayed after this output amount. Hence, this subtemplate combines the functionality for both typical units and Na units (such as "acre"), allowing for the eventual removal of "-Na" suffix subtemplates, to reduce the total for Convert (this template would become contents of Template:Convert/LoffAonSon).
This uses: {{convert/outadj | amount |{u}|{h|{n}} }}
to display the output amount and unit symbol/name. This template can be invoked by any multi2, or multi3, subtemplate to show one of the 2 or 3 output amounts+unit.
NOTE: If {u} is accidentally not defined, then -{h} or -{n} will be displayed. Check usage in callers to ensure {u} is defined, if applicable.