I really don't understand why they make you enter charge max capacity. When charging Lipos the charging method is CC/CV. So it charges at constant current(CC) until the voltage reaches 4.2v per cell. Then it charges in constant voltage mode(CV) until the mAh drops to a certain percentage and the voltage stays at 4.2v per cell.
Here is what I would do with your charger. Set it at the maximum mAh for charge capacity. This will allow you to charge higher than 5 amps. Any Lipo can be safely charged at 2C so in the case of your 5000mAh this means it can be charged at 10 amps but the ICE only has 8 amps maximum charging current. So if you set your max charge amps at 8000mAh you will be able to charge at 8 amps. Hope this makes sense.
One is welcome to use a very nigh number for the max capacity. It's only there as another insurance against an overcharge. Just in case something gets set wrong or screws up. It has nothing to do with the rate or the termination point. It will simply stop IF that capacity gets reached. I do believe it is a "leftover" from the NI days.
I haven't messed around with an ICE for a very long time but if I remember correctly it will only allow you to charge at 1C so if you set the mAh at 5000 then 5amps then it't the max you can charge at. This is why I think it's best to set the max mAh at 8000 then you can charge at 8amps which is fine for a 5000 pack. But I could be wrong as I haven't played with this charger in so long.
Been to long since I played with this charger. We used it as cheap way to charge packs when we use to cycle them 4 -5 years ago. Really can't remember exactly how it was setup but I know we had to trick the charger to charge at 8 amps.