unable to build with pandoc/basictex minimal

[psifertex]

It looks like the default basictex minimal package (90mb instead of 5gb!) includes xelatex but does not include the font required to render the U+FF3F full width underscore characters on MacOS 13.3.

The specific error is:

WARNING] Missing character: There is no ＿ (U+FF3F) (U+FF3F) in font [lmroman10-regular]:mapping=t

I assume there's simply a different font being used by default in the full installation? Is it possible to document what font can be specified via the -V 'mainfont:' CLI parameter so that it's buildable with a more minimal latex install?