You're right that you will lose €23 at most - if you cancel.

But if you change dates, or change itinerary, you will make no savings whatsoever - you will have to pay the going fare for your new journey in force on the day you decide to make the change. In fact, by holding a "Flex" ticket, you may be required to also buy a Flex ticket for your changed ticket. In that case, it would just be cheaper to have waited and bought the cheapest-available ticket offered for sale on the A3 website to those passengers who are only just booking a ticket for the first time (in the worst case scenario, of course, there may only be Flex tickets left for your new route and date, but the chances are that a cheaper ticket may still be available than the one you're forced to buy). Of course, if you wanted to have a Flex ticket (more miles, better conditions) even when making a relatively-late change to your ticket, then that's OK - but beware that it may not be allowed/possible to change your "Flex" booking into a new "Light" ticket, even if Light availability is offered on the website for people considering a new purchase.

Even if you decide to change dates/itinerary, it may still be beneficial for you to instead cancel your existing ticket (losing €23) and simply buy a brand-new ticket at the cheapest rate from the A3 website (or whatever Online Travel Agent you like)

If you do decide to change dates and/or itinerary, please come back and document your experiences! And good luck/safe travels