As with the introduction of Light Hotspots and with the conversion of Full Hotspots to Light hotspots, with updated Firmware, there is now no longer a need for network port 44158 TCP to be open on your wireless router or Ethernet switch. Light Hotspots only initiate outbound connections to Validators, and all consumer routers allow all outbound connections by default. As such, Light Hotspots only need to be connected to the Internet without any further configuration.
You can check which Firmware version you have by accessing the local diagnostics on your Nebra Hotspot. By default, they should all be updated automatically OTA. To access the local diagnostics you can see the guide here - https://helium.nebra.com/#/handy-guides/local-diagnostics.md
Since the upgrade to light hotspots you no longer need to forward port TCP 44158. If the hotspot is showing as relayed in the Helium Explorer it may take a couple of days to update.
Miners no longer need to be fully synced to 100% as long as they are above block height 1350604 (This will be removed from the diagnostics page shortly). Since the latest Firmware update, any hotspot past block 1350604 will now show 100% synchronised.
Yes, you don’t need to do anything as this will take place automatically via an OTA update, your miner will still be able to earn when the transition has taken place.