changing to linux will not sort your problem, all that will do is to give a massive headache.

Right getting on to the real problem, the simplest way to cure this is to lengthen the "pawl", this is the rectangular part that catches on the rachet wheel. Similar tool changers to this have an adjustable end stop for the pawl which sets the tool position relative to the centre line of the lathe.

Or you could raise the whole tool changer to match the centre line, but this may give your tools a bit of positive rake.

I'll pm you my mobile number if you need a chat.

Tom.