Data persistence to influxdb 1 instance and influxdb 2 instance at the same time in OH3 or OH2. Possible?

Running OH3 in Docker. is it possible to have OH 3 save data to 2 influxdbs instances at the same time?

No, I think there is just the one InfluxDB add-on that supports either InfluxDB version based on settings. It won’t link to more than one DB server at a time. And even if it could, you wouldn’t be able to define a different persitence strategy for each one.