Are you,... ********?Reason why I do jab 1 instead of jab x2 is because since it's faster, you're more likely to catch the opponent off guard and get a follow up like a grab or ftilt. You just need to mix it up between using jab x1 and jab x2.
Look, Marth can UpB out of every single follow-up Falco has for jab1 (including shield and spot dodge) aside from jab2. Jab2, however, can be followed up by shield and will stuff Marth UpB, allowing for a free follow-up. This lets you mix-up Marth out of jab2 because he's afraid of your shield. If you are prone to use jab1, then if Marth didn't UpB you, he didn't take the completely safe option and he should be exiled from Smash Civilization.
No, it's not about mixing up jab1 and jab2, it's about mixing up after jab2 in this MU.