Isn't it just a software modification and/or an extra button on the panel? Cannot be a heck of a deal as airlines like Lufthansa and Alitalia use the E190 without having bought them outright for LCY operations. So while the E195 might be restricted because of its size, I don't see a reason why the E175 should not be able to operate - or does it have tailstrike problems given its longer fuselage with the same undercarriage as the E170?