I'll second
@nereefpat assertions.
I would say they are correct - if your overflow can handle it, than there's no issue with increasing flow. The only thing you may need to do, is figure out how much more water the systems needs to maintain levels in the the sump.
If you want to find the maximum (safe) throughput that your overflow can handle - here's how I do it.
Start by opening any drain valves you have wide open. (the drain will get really loud).
Then, increasing your pump 5 to 10% at a time, then waiting few minutes while adding water to the sump as needed to maintain the level in the return chamber.
Each time it stabilizes, increase another 5 to 10%.
At some point you may notice that the display tank will begin to fill up faster than it can drain - this will be the flow rate outpacing the drain. At that point reduce the pump 10-20%, and let it stabilize.
If you reach 100% on the return pump, but your not overrunning your drain, then just just move on the next step.
Finally, adjust your drain valve(s) to make it quite. Once you have it dialed in, you may need to remove water from the system to maintain the proper level in the return chamber of your sump.
Now that you have more flow going through the display tank - you might consider add the
Random Flow Generator and take full advantage of that flow
