I hate to say it, but that describes a lot of today's TWS buds. There are very few that will allow pairing with more than one device. You have to power them off (or the BT transmitter on the device) and then pair them with another device. I would love to have this feature more also to be honest.I had P14's and the ANC was non existent as well as all same issue you can read from Amazon customers, I see the P17's do not have any way to pair to another device or power on/off without the case, deal breaker for me.
There are quite a few that will "auto" power off after a time of no activity, but there is usually no way to manually power them down. This seems to be the trend in the TWS market. I would love to have some way to manually turn them off, but I don't really see that feature coming back.