For some time, the far-reaching and speculative idea of using the Sun as a gravitational lens has been floating around. See this and this. This would require sending a spacecraft about ~550 AU of a distance away from Earth, so the idea is not currently realistic.
But I am wondering, is there any plausibility to using other stars (like the Alpha Centauri stars)?
Is there there enough parallax for this to be useful? How far away must a satellite go to be able to manipulate parallax to its advantage? Are there any shortcomings to this idea that make the FOCAL proposition superior? And of course, are there any shortcomings to both propositions?
I'm curious if anyone can give useful feedback or calculations.