Hey Chris,
no, as I explained (unfortunately also in the post in the other thread) is that there are not only one register that can store a Z offset, I showed two different registers, the usual workpiece origin offset (#5213 for Z), and the tool length offset in the tool table (#5403 for Z) which changes according to which tool is selected with Tx or with G43 Hx. Both are shown in the “offset” column on CONTROL page when they are in effect.
If the g-code output of your favourite CAM program does not issue M6 commands, you probably have not set it to do so. I know Carbide Create puts the tool number in a comment because it is only honoured by their own CNC software, but with a modifying script you can change the comment with the tool number easily to M6 Tx. But I know Fusion360 exports g-code with M6 Tx commands if it is set accordingly. Look if you find the setting and you will see that the tool number is honoured by the Onefinity Controller.
Also you don’t forcibly need an automatic tool changer to benefit from the tool numbers. You don’t know my ‘tool-change’ routine for manual tool change on the Onefinity Controller? It pops up a window which asks the user to insert the tool by its number, according to the T value given by the program.