What people think they know.., because
Currently, it is 2x 1,900 euros net (he+she), soon it will be 1,900 euros net he + 1,200 parental allowance she (+ child benefit)... so we are currently talking about 3,100 euros in the first year, after that about 3,300 euros net. I am not a fan of selective reading.
The AXA offer may be the most flexible offer at the most expensive conditions. But I consider it (except in a few exceptions) the wrong one.
So now to A1 and A2: From the perspective of the ZiÄR, whether 197,000 euros are open in 15 years or 173,000 euros in 20 years is absolutely irrelevant. According to the motto... paying off faster is best, I would take A1 for 15 years with the rate from A2.
The offer of the two-time repayment rate change should be completely sufficient, because as long as you cannot suddenly repay more than one installment of over 2,200 euros monthly (installment + 1/12 of the special repayment option), you do not need the (also dearly bought) option of repayment rate change at all. Simply put the extra money aside monthly and repay once (or whatever the contract offers in terms of special repayment fractions) additionally.
The option of repayment rate change should only be used in two cases at all:
1. Unforeseeable events like unemployment, triplets or God knows what
2. Excess money in the form of an extreme amount (see next point)
By the way, that is the only reason why I would want to take offer 3. The prospect of regularly using the special repayment in full already in the coming first years in combination with the possibility of wanting to repay significantly more monthly. But there is no indication of this from the available information.