iX3M2 is equipped with BLE Bluetooth and is can be connected to smartphones.
We are developing the app for the smartphones, it will be released in late 2023, but I do not have a release date yet.
At the moment I know that third party app (like subsurface) already works with the iX3M2 Bluetooth but they are very basic.

Yes, press D button (last button on the right). The clock and battery will appear in the center-bottom part of the display.

Note that The clock in the dive mode has been added in with OS 5.1.9.
To update your unit use the Ratio ToolBox available here:
https://www.ratio-computers.com/support/support4/support_toolbox_main.htm

When fully discharged the iX3M2 activates the "battery safe mode". iX3M2 uses some % of power to preserve the battery from over discharging (over discharging badly damages the battery). This means that iX3M2 will take 1-2 hrs of recharge before to deactivate the "battery safe mode" and turn ON.

Double check that the USB adapter is connected in the right way.
Here the video tutorial: https://www.ratio-computers.eu/en/content/13-ix3m-2-video-tutorial

It is not possible to delete a single log from the logbook of the iX3M.
It is designed as a "black box" and it cannot be alternated.

It is possible to erase the whole logbook sending the unit in Ratio Computer Lab for a service.

The iX3M2 adjusts the backlight semi-automatically.
You can set a level of brightness from 0mt to 9mt and a lower level below 9mt (the switch is automatic).
So you will have a very bright display when you have a lot of sun-light and you will save battery when a super bright display is not needed (or can be too bright).

To connect using the Bluetooth activate the PC MODE on the iX3M2, than use your smartphone to pair the BT (Settings -> Connections). If required the pin/password/confirmation code (it depends on the smartphone) is the S/N of your unit (you can find it in the PC MODE screen).

The iX3M2 Tech+ has no connector for the sensor board, so it will work with the Rebreather as external unit (you can set 3 Set Point and choose if the unit have to change them automatically (based on the depth) or manually), but it is not able to "read" the O2 values coming from the rebreather's sensors

The signal sent by satellites is reflected off the water's surface, so once submerged, there is no more signal. The GPS navigation system works best when out of the water.

As you can see from the image below, the iX3M2 GPS displays the current point and the target point and indicates the direction to follow using the compass.

When the GPS signal is lost, iX3M2 relies solely on the compass to try and indicate the correct direction. This means that the longer time passes, the more the direction indication becomes inaccurate. The indication becomes precise again as soon as the iX3M2 GPS is able to locate its position again.

The system, therefore, is designed to be used out of the water or when approaching target points with planned resurfacings in order to compensate for course errors due to drift, currents, etc.