Sure, you could fly a gravity lensing telescope in the near term, but you wouldn't be pushing the envelope, because it would just be an ordinary telescope. Instead you could spend those same resources to move closer to achieving the ultimate telescope. Radical advances could be made in the near term. The gravity lens scope would just delay and push back the schedule and waste money that should be spent on things we really want to do.

The universe is large. The galaxy is big. We can't spend time looking at one or two stars. We need serious speed, information processing, and optical power. Even my gi-normous telescope array would only observe, maybe, a million planets a year. That's a tiny fraction of what's out there.

We need to develop the ability to scale things up, to continuously advance. Token efforts, while interesting, wouldn't really get us anywhere.