Lowering the Sportster using the brackets is not necessary, and as Glider says, lowering the bike MAY introduce problems. That said, a lowered Sporty is easily accomplished with changing shocks to shorter ones by Progressive AND lowering the fork by installing Progressive Springs and spacer based on riders' weight as well as changing the fork oil to 7.5Wt (from 5Wt), lost about 1-1 1/2"...then changed the seat (to put on a 4.2 gallon tank),lost another 1-1 1/2".
Since my mid pegs were pitched along time ago, so no "feelers" on the ends, I did scrape slightly on the left (jiffy stand tang), but I trimmed 1/4" of the rubber bumper stop tucking it in by almost 1" and changing my aftermarket exhaust bolt hardware to proper length so even in off camber on/off ramps or in deep turns heeled way over, I no longer have "sparklers". I also have modified my riding style in turns to stand up the bike, apply pressure on the outboard peg and keep my body towards inside of the bike.