Like @Cobra said, barring the couple public examples Hubitat provides on Github, the internal ones are not made available. However, there are LOTS of examples of different drivers out there. So if you are willing, you can always find one that is close to what you want and modify it to suit your needs. Just make sure to properly attribute where it originally came from if you do.
Most people are happy to let others use their published drivers... But you need to make sure to follow the license provided (usually it just requires that you acknowledge the original creator/contributors).
Last, there is a thread out there now for people to bring up missing features or missing drivers for Z-Wave devices. You can make a request there. Here is a link.
