I have always installed and bled my 1954/55 replacement original-style single-chamber master cylinders and brake lines as described in the Chevrolet/GMC Shop/Maintenance Manuals. I do not recall seeing instructions on bench-bleeding the master cylinder.

If I used non-original-style dual chamber chamber master cylinders and/or disc brakes, I'd bench bleed.

I have no problem seeing that people recommend bench bleeding. But, I have had good brake pedal since 1968 (except once, when Jim Carter sent me a worthless/pitted replacement/new master cylinder).

Tim
1954Advance-Design.com
1954 3106 Carryall Suburban
1954 3104 5-window pickup w/Hydra-Matic
The 216 and early 235 engines are not "splash oilers" -- this is a splash oiler.