Yes some launches such as the recent VEGA are into elliptical orbits BUT they have very short lifetimes before burn-up, I think the VEGA orbit is only 2 years. Ideally we'd want an elliptical orbit that would last 15-20 years I don't think any standard launches do that.
The costs of buying a launch to an orbit we'd like will likely remain prohibitive so it looks like we need to develop our own propulsion to take us from a "cheap launch" orbit at 350 or 700 km to one above 1250 km that'll permit DX working.
I think we'll find it easier to raise perigee of a short lived elliptical a bit, rather than raising a low circular to a stable high LEO or elliptical. But, I don't know for sure. I'm a geologist, a rock scientist, not a rocket scientist!
AND! the propulsion depends on 3 axis control, which seems to be worked out well commercially now for 3U cubesats.
73, Drew