I think many people just don't bother with Stellar Manipulation.
Except for the fact that you can construct Ringworlds and Sphearworlds later on, Researching Stellar Manipulation is an unnecessity.
Monolith Facilities maybe tempting as they can extract 900 of all "moolah" types, but they still depend on the percentage of production of the planet, and 100 minerals, organics, or radioactives are lost with every Monolith.
The power to create suns and planets may be tempting, but you can't create planets without Asteroids, You can't create suns unless nothing is in the darn thing, Nebulas and Black Holes actually become beneficial later, even with scanners because of the system abilities and Storms has no absolute value of investing in them unless you want to hide some ships or shipyards in them.
The only about useful Stellar Manipulation techs are Warp Point Creator when you want to cut a shortcut or some parts are cut off from the rest, and Warp Point Destroyer as a way of ignoring those psychotic races.
And Without cheat codes, building ringworlds and sphearworlds will take you lots of time...
Hope that helps