Test report (see attached image).
I had been searching for a way to join two ropes that results in a very small footprint - even smaller than #1410.
I noticed this possibility while playing around with Xarax's Riggers X1 bend (which is topologically equivalent to Ashley's #1426 Twofold overhand bend).
Initially having high hopes...but shattered when I ran several tests - finding that the structure becomes unstable at loads less than 1.0kN (using same diameter ropes).
Trying again with different diameter ropes did boost the instability threshold... but only to approximately 1.1kN.
Interestingly, the structure morphs into a 'false Butterfly' (my term) - which then jams at approximately 3kN (can only be loosened and untied with the aid of tools).
Oh well...