Any L-shape dovetail or something?

Altazimuth mounts have a vertically mounted clamp for dovetails.
In such a way a scope must be mounted 90 degree tilted (dovetail on its right or left), the optimum being a dovetail BELOW the scope. Practically speaking the scope is cantilevered.
Such a configuration, especially if the scope is a heavy one, can induce tensions to the structure/optics, giving non-simmetrical star test patterns
I guess tensions are probably higher then an horizontal dovetail mounting.
I’ve been looking for long time for an L-shaped adapter, or something, capable of mounting your scope ABOVE its dovetail (horizontally clamped dovetail, instead of vertically clamped) but I found absolutely nothing.
Does anything like that exist for altazimuth mounts?