Bravo, mikerjf!!!
You certainly enhanced the "pocketability" of your 457.
I commend your handwork.
While there is no doubt that guzzi is the "master of the milling machine" ("Baron of the Bridgeport"?), with the file skills you have displayed while truncating the grip frame, I am convinced that you could have made the "Hi-Power" cuts yourself.
Our Forum Member "squidsix" has been known to add (by hand) the "Hi-Power" cuts to a slide or two.
IIRC, leaving the manual safety while removing the disconnector would allow the trigger to actuate the hammer even though the safety was applied.
Granted the firing pin is both blocked and arrested, I would be concerned that
for me, in the "gravest extreme", I would be pumping away at that trigger and wondering why my opponent seems unfazed

, until I realized the safety was still on.
Again, that's just me.
I'm sure you have trained for that contingency.
I would probably go the next step and install the DAO "firing pin retainer" (manual safety plug), and maybe even substitute an easily fashioned "take-down pin" for the slide stop, for the ultimate in slim.
Anyway, again: Nice work.
It's great to see Forum Members displaying their handiwork.
John