Multiple frequency plans on single TTN V3 application?

For high altitude balloons flying across several LoRaWAN frequency regions, on the V2 application, packets are routed to us from gateways in USA/Canada/Japan as well as the EU. No need to mention frequency plan when setting up the application. The tracker switches its frequency plan depending on where it is. We use ABP for activation. And we specify the Handler as ttn-handler-eu.

However, on the V3 application, it requires me to specify the Frequency plan. Does this mean the devices registered on this application cannot switch frequency plans at all and must stick to the same regional frequency plan?

If so, are there workarounds for using a TTN endnode around the world on all frequency plans?

I know that TTNv3 has not yet been made available in the US/Japan yet so I don’t think it is time to switch the trackers using TTNv3 yet.

Many thanks