Assuming the Landi system is a piggy back unit the same as most other multipoints, it doesn't use the lambda sensors, just displays them on the screen as an aid to fault finding. Changing it to 2 will probably give you a display of both (assuming they are both connected).
The P38 I've got with an egas system on it is also set quite high so I have to give it some revs to force it to change over. My main one on a single point is set for 1200 and I intend changing it on the egas too once I get it running on all 8!
Can't help you with 3 though but I would have thought 2,500 would be high enough for a low revving P38 motor.
Don't know enough about the Landi software to say if it will automatically save any changes or not, so can't help on that.
'96 Saab 900XS, AEB Leo, sold
'93 Range Rover 4.2 LSE, Lovato LovEco, sold
'98 Ex-Police Range Rover 4.0, Singlepoint AEB Leo, my daily motor
'97 Range Rover 4.0SE, eGas multipoint, a project.....
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