The autoselect feature in Studio is no longer hidden behind a query parameter and is also able to select disabled elements, see https://github.com/phetsims/studio/issues/243. The documentation should be generalized in phet-io-guide.md for all sims (and the template). However, there is an additional feature being considered to highlight model elements in https://github.com/phetsims/studio/issues/246.
autoselectSupported is documented in density, molecule-shapes, and molecule-shapes-basics and will need to be amended.
See https://github.com/phetsims/phet-io-client-guides/issues/18: