On a creed...would you lower the LPR to 280fps and then lower the dwell? or just lower the dwell so the marker shoots 280fps? Or whatever the fps desired...
As for creed you adjust dwell down to get best consistency then set pressure accordingly to reach desired fps.
Most markers are perfect around 10.0-10.5ms on the dwell. Then reset regs to get smoothness, efficiency and softer on paint.
If you go to low on the dwell you will see spikes in velocity and if your regs are unbalanced you will break paint. This is the point were the fine tuning comes into play. Ypu just need to find that balance and it will be perfect