That was probably a 3 button panel CP to begin with given the 1P bottom row. Seems to me like this person was bent on playing Neo, I think that's why he added a select button at top, or it could be a credit/coin button, either way I think it's horrible.
I know lots of folks go for the 7 button setups, hell even Taito did on their new CPs but damn it I just don't like it. Actually, come to think of it the vewlix 7 button setups are kinda cool when the 7th hole is plugged 'cause the CPO art surrounds it like the rest of the buttons.
When it comes to Astros I just simply swap a few quick disconnects trun my wrist slightly inward and I'm playing 4 buttons style no problem, but I think I started getting used to that when I started playing atomiswave games and playing them on a 6 button panel with the 4th button plugged. It works awesome!