I no longer think gift wrapping was the right play for private events like I used for nostrcal.com. I'm interested if anyone is using this kind of functionality on the project?

While gift wrapping creates excellent privacy for events, it also doesn't work well with bunker signing. It's also kind of computationally wasteful since you have to download all of your gift wraps and unwrap them all to find the events that you want to use. If more event kinds start publishing wrapped versions then you lead down a path where you may need to decrypt way more than what you need.

I'm starting to think that privacy may be better provided by the relay with auth for the calendar use case at least. Users can define their home relay, or a relay they trust, for their client to know where to go then rely on the relay to limit access instead of wrapping. You're trusting the relay with your event to keep it private but the privacy conscious are likely already running a relay to backup and store their notes anyway.