It looks as if one would normally machine a ~3.3mm hole, then the tool is plunged into the center, then it moves sideways to begin the cut, then spirals up and around and out (this allows chips to fall to the bottom of the hole, rather than worrying about clearing them).
If the above seems reasonable to you and the tool and collet are in your budget for this project, let me know and we’ll see about doing the code for it.
Really appreciate your help and offer to share the code.
After some consideration: I don’t have fusion360 and don’t want to pay for it (commercial use), I don’t have a 3mm collet (well I do - but it’s for a 2.2kw spindle that isn’t installed), don’t have the thread cutting tool, don’t have the knowledge to carry out the task.
I think I’ll have to attempt manually tapping the holes with a custom tap and re-assess automated threads at some point in the future.