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Only for very small aspect ratios (like on the F-104) there is an appreciable effect on maximum lift, as the lift distribution becomes very close to the elliptic one.
I would have always thought that for a given wing-loading a higher aspect ratio would always produce a higher peak L/D ratio than a lower aspect-ratio.
The main factor is that the induced drag gets significantly smaller with higher aspect ratios making the wing more effective.
Induced drag = drag due to vortex formation on the tips?