I think with chase you can leave the amount blank and they will see what comes back and then if you don't like it recon. It is a HP though. I got a $1000 CLI on a recon once I asked for $500 but the gave me more
You should be fine since you have had it for three years and have no recently opened accounts. All credit limit increases are a hard inquiry if you request them, but some people contacted the executive office to request an increase with a soft inquiriy done.