Phils will never fail.. the axles dont bend the main advantage to seeking out an old freehub is they shift the bearing to the outside edge of the freehub driver.

You would need an old 6~7 speed free hub to get a reasonable 126 wheel
I had a Phil freewheel hub (with 48 spokes) on my Touring bike rode a lot of gear on the rack touring with my camping gear
on some pretty rough roads for a few years of combined tours..

a solid axle will be stronger than a QR one, but If you dont go that Phil way a broken QR axle is cheap and quick to replace.

New Phil FSA axles can be altered with a few parts.. to keep them, lifetime..
when you fit onto the next frameset.

then again If you drop the derailleur thing entirely, and switch to a Internal gear hub
Alfine 7 speed perhaps?
a number of strength advantages arise from a dishless wheel ..