I don't know what you mean by "steering lock", and I'll infer that you're talking about steering stability and getting the steering to a dangerous wobble that hits the stops.
The steering would not wobble easier than stock, and did not display any unstable or anti-stable tendencies. I could let go of the (DSR) steering at speed and not get a wobble unless the pavement perturbed it, and then it was very calm to correct. I don't know about an SR's tendencies.
I was honestly more concerned that the fairing mount fatigue would add up and drift the dustbin downwards or allow wobble that the wheel might scrape on. This did not happen, thankfully, and I logged about 20-25k miles on it before switching to the Hollywood Electrics fairing.
I will also say that the square-ish profile of the DBL2, unique among these fairings, reduced my lean angle noticeably to the point where I had vinyl strips on the corners to absorb road scrapes. For what it's worth, the DBL2 is the "show bike" dustbin, and is featured on most retro mods involving dustbin fairings. It's an impractical fairing.
Finally, I am not riding yet, except those urban rental sit-down scooters in full gear a few times. I'm getting my stomach tube removed on Monday which leaves my face and dental surgery to restore upper teeth as the limiting factor over the next couple months.