Actually why do you switch it OFF?

Keep it ON until you're ready to switch OFF, 1 or 2 minutes in addition is irrelevant for the battery (the led lights - front and rear - have very low watts).

I have just got the reply from my Soco dealer, saying that alarm reprogramming is not possible 🙁

Unfortunetely dealers are unable to do many things because of lack of knowledge... and it's not only for super soco, but for all motorcycles and cars. 

The manufacturers know and have the tools to change many parameters (including re-flashing the software), but dealers are just intermediaries who buy and sell with a profit to survive.