It's not about whether it's possible, it's about why you'd even bother. I mean, think about it. There are hundreds of member planets in the Federation -- they can't all have exactly 9.8 m/s^2 surface gravity. There must be plenty that are in the 0.9-1.1 g range, and humans live on them just fine. It's close enough that it doesn't need to be "fixed," because there's nothing wrong with it.
Heck, if anything, a moderately reduced gravity like Venus's might even be beneficial for human health, because it would reduce strain on the heart and skeleton and joints. People might actually be better off in 91% gravity than 100%.