Does Zcash support timelocking private funds?

Continuing the discussion from Delaying transactions/ timelocking Zcash.

In 2018 @bitcartel wrote that Zcash’s ability to timelock transactions were limited to the public pool since we had only inherited this from the bitcoin codebase. Is this still the case 7 years later?

  • Are we able to timelock some private funds?
  • Follow-up, possibly more advanced, are we able to prove we locked some funds?