As you found, employer plans like your 401(k) are not required to offer in-service distributions for this purpose. Many plans are in the process of updating their plan agreements to include this optional feature, but until this feature is adopted by the plan such distributions are not available from the plan. On the other hand, IRAs are not subject to limitations on distributions.
Although the IRS has not yet provided guidance for this provision, this provision is similar to that for a qualified birth or adoption distribution, so one might expect that the IRS will require it to be reported similarly. If so and the recipient is under age 59½, the payer will use code 1 to report the distribution on Form 1099-R and the recipient will need to claim the penalty exception (yet to be assigned an exception code since this is new for 2024) on line 2 of Form 5329. Although exempt from penalty, the distribution is still subject to ordinary income taxes.
Regarding possible repayment within 3 years, the IRS has provided guidance on how the IRA custodian is to report the repayment on Form 5498 but I don't think that the IRS has yet provided guidance on how the individual is to report the repayment on their tax return. It might be that the individual would need to amend the tax return on which the distribution was reported and report the repayment as a rollover.
