[You guys are fudging the definition to win a debate...]
No, I just posted a link for stripper clips for an M1 Carbine. All stripper clips are in effect “magazine fillers” as you put it. The Broomhandle Mauser pistol also used stripper clips. Their purpose is to basically fill a magazine while still installed or part of the firearm.
The difference is more with the magazine itself. Whether it is fully removable or fixed or hinged (Ex. SKS)
The En banc clip used in the Garand melds the magazine and clip into one integral unit that works together to form an assembly. Once the “clip” is empty it is ejected and a new, loaded clip is inserted to form the magazine assembly again.
While I do enjoy your lessons on weapon technologies, the distinction to me is between magazine fillers used in the rear such as you refer to for the M1 carbine and stripper clips used reload during combat. Stripper clips like those used for the Broomhandle, the K98, the SMLE, the ‘03, the M1895 Lee Navy, etc., etc, to provide reloading in action and other than single loading are the only way of reloading in combat.
It is stretching the definition to include conveniences for loading magazines in the safety of the rear to devices that are integral to the design, i.e., having milled slots in their receivers to accept stripper clips.
One is part of the weapon design, the other is an accessory.
P.S., the M1 clip is en bloc, not “en banc”.