Is it program in the comfort access option into a BMW using the VVDI2 Xhorse?

Here you go.

That’s not possible to just program. It requires major hardware exchange

There’s 2 difference key types.
Regular smart keys and comfort access keys.
The key needs to have a build in proximity sender and the car needs to have a receiver.
You can’t code a regular key to become a comfort access key.

Then you need to first delete a previous CA key from the CAS module. Each CAS can only handle 2 comfort access keys at a time. If you lose, let’s say key number 2, then you’ll need to first delete key number 2, program a new key and then move the keys individual number up to key 2.

Btw, It is not the same meaning as you over-write key2 with the new key (by eeprom). In other words,  Eprom has nothing to do with CAS control

Comfort access can only be in slots 1 & 2 unless you disable all the slots up to yours ie program slot 5 and disable 1-4. Or you just overwrite slots 1 & 2.

To overwrite the slots when selecting a slot that have been already taken, Need comfort access fob as well. I’ve actually never done I always use slot 7. Auction doesn’t care if it has comfort or not lol

Good to know:

What is Keyless Entry?

Keyless Entry or Passive Entry is a terminology commonly used in an automotive technology, which locks and unlocks a vehicle without using a conventional key and/or pressing the buttons on the Remote / Smart Key.  However, Keyless Entry DOES NOT mean that ‘there is no key’. Rather, it means that ‘there is NO need’ to physically enter the conventional (metal) key into the lock/ignition as was the case in the earlier generation cars.

When you enter the vehicle with a Keyless Entry / Smart Key, you can start/stop the engine, without actually inserting the car key into the ignition switch. A built-in transponder of the Smart Key identifies the vehicle to which it is ‘associated’ and automatically activates its ignition. As a safety measure, a vehicle cannot be locked so long as its Smart Key remains inside that vehicle. However, Bosch is going ahead when it comes to technology. Bosch recently showcased new technology to the world called Bosch Perfectly Keyless.

What is a Smart Key?

The Smart Key is a sophisticated, ‘computerized’ key; which accesses and unlocks the car’s locking system electronically. It replaces the conventional / metal key in modern day cars. Siemens developed the electronic Smart Key system in the 90s, while Mercedes-Benz used it first on its S-Class in 1998 under the trade-name “Keyless Go”.

With the Smart Key kept in the pocket, the driver can lock/unlock and start the vehicle. The vehicle identifies its own Smart Key from the radio pulse generator in the key housing, which detects the radio signal thru’ one of the many antennas fitted around the vehicle. One can unlock the vehicle, by simply pressing a button or sensor fitted on the door handle. Additionally, the Smart Key system comes with a Start-Stop switch. In case of loss of the Smart Key, you can still unlock the car with a spare key-blade (without electronic circuitry) supplied by the manufacturer.

The Smart key can unlock the immobilizer and turn-on the ignition without inserting the key in the ignition switch; so long as it remains inside the car. When you enter the vehicle with the Smart Key in your pocket, you can start the engine by simply pressing the Start-Stop button.