How would this really help anyone? Most OCI holders will still need to carry their national passports for travel out of India when they need to leave, so you're not saving on carrying just one document. The set of people who need to travel urgently to India on their OCI but who don't have a valid national passport must be vanishingly small.

Much more practical and useful (IMO) would be the following:
* Change the format of the OCI to be a credit-card size document (like a US passport card, "green card", or Global Entry card, or driver's license, etc.) so it's easy to carry. There seems to be zero need for the paper pages in the OCI (has anyone heard of any endorsements or remarks being added in the OCI booklet??)
* Just declare it as sufficient as an ID for most things in India - hotels, domestic flights or other travel, getting a SIM card, or 1,001 other things an OCI holder might want to do in India on a short or long stay.