Some twenty years ago I came across an article on a steel frame possibly 753 custom built by a German frame builder. Besides having a very tight geometry, the frame hada rear ward facing track style dropouts. The derailer mount could possibly have been welded on. The rational being that once positioned, the spring of the derailer actually pulled the wheel into place.
It seemed a novel idea at that time and I wonder why the trend did not catch on. Anyone else heard of this?

Several frames are now made this way. Both the Surly Karate Monkey and Soma Juice have derailleur hangers and track style fork ends but this is for versatility so they can be built as derailleur, single speed or IGH configuration bikes.

IMO the derailleur spring is not strong enough to have much effect on wheel retention and almost all high end bikes of the era used semi horizontasl front opening dropouts which allowed fitting adjustable wheel stops. These allowed more rapid wheel changes with proper wheel alignment.

the reason that rearward facing drops didn't catch on is that it's a pain to change a wheel. There are dropouts made now with rear facing slots and a derailleur hangar, Paragon makes them. If there was never any chance of using a fixed/ss/igh I would never use them though.

Klien had a bike like that for awhile. a customer had one and it really was a huge pain to R&R the rearwheel.

If the chainstays are to be real short, the wheel cannot be removed from a forward facing dropout.

rear facing dropout gives you the option of a fixed gear wheel so there is a way to
tension the chain.

dropping the chain off the chain ring gives you more slack to play with
if you have a RD on the thing.

I test rode a Storck Absolutist that had backward facing dropouts. Nice ride! Equipped with the Red group. Anybody have $7K they're not using?

LOOKs time trial bikes (at last I checked) had horizontal drops and a hanger.
The definitive advantage they still hold is in being able to shift the rear wheel as close to the ST as possible for more aeros!

Klein microdropouts face rear but they are not like track ends... there's no chain tensioning adjustment possible. And changing a wheel is not hard at all but it fools people who've never done it before.

Thanks for the info. love to see any picstures (if someone has them) of any of the frames mentioned above. I am enlightened by the general observations. that rear facing derailers were necessary to mantain such a tight geometry. I can also appreciate the fact that no rear wheel adjustment is possible in this configuration. I thank all for the time taken to respond to this thread.