I come across a lot of ice tank setups that are not optimized in routing or flow and the results I see are lack luster in those cases.
With that said, here's how I would set things up.
If keeping the heat exchangers in then I would disconnect the bottom hose going into the supercharger. This line will now return to the tank, you can modify or replace this section of hose depending on how you decide to route the lines from there.
The feed line will run from the tank into to the supercharger input lower port. Everything else would remain the same.
You can run the lines either underneath the car or with a lot more work, through the cabin into bulkhead fittings on the firewall. Use heat protective wraps when routing anywhere close to heat sources like headers/exhaust.
This will retain the factory pump which I feel helps to overcome the additional head pressure of going through all the extra loops and turns.
For racing at the track, if you set it up to be able to turn off all water pumps until it's time to start up the car before going through the water box, most of the ice you load up before hand will still be there for your pass. Ice can last for over an hour in the tank in the staging lanes if you can turn off all pumps until it's time to use it.
When leaving pumps off in staging lanes, it's recommended to occasionally run them for brief moments to lessen the shock later when you turn it on. Either that or modulate them until you're comfortable with letting it run full time before pulling up to make your pass. I generally prefer the 2nd method myself. The sudden cold temperature shock has been known to cause intercooler bricks to crack and spring a leak. Pretty rare but some simple procedural steps and you can minimize risk here to almost nothing.
If you bypass or delete your heat exchangers then you can get away with a single water pump but it's going to get real hot if you drive around without ice for extended time.
Having heat exchangers bypassed or not only affects head pressure. With heat exchangers in, you may have less flow which can in turn lead to less heat extraction from the intercooler bricks. That's why I recommend keeping the factory pump in that scenario. I also have not found a "limit" yet on having too much flow in terms of how it affects IAT's. The more flow I can get, the lower my IAT's have generally been as long as there's enough ice water capacity to feed the supercharger during the run. I generally run 5-7 gallons myself which is plenty. If you're running less water capacity then you'll run out of ice water sooner with more flow which can lead to higher IAT's later in the run. In such scenarios, less flow might actually be better overall. Lots of factors at play and only real world testing will reveal what's actually best for a particular setup.
Here are some common routing or setup mistakes I see a lot.
Ice tank is plumbed to feed into heat exchangers first before going into the supercharger. Ice cold water will warm up going through the heat exchangers leading to warmer coolant feeding into the blower.
Kinks in the water lines restricting flow. Flow restrictions will result in a sharp rise in IAT's, worst than stock. It may start off good but then shoots to over 200F by end of the pass because of some sort of severe restriction in flow.
Air locked system, this shouldn't occur if you have a pump at the rear of the tank that will always have water to push through the system. I've seen some weird ice tank setups though where the pump is remotely located and would cease to pump water under hard acceleration.
Insufficient flow due to excessive head pressure. It works despite this but it's not as good as it could be.
Factory reservoir not addressed causing air to enter system and cause an air lock. The factory reservoir tends to suck air in through the radiator cap with rapid temp changes occurring in the system. You can also cap off the pressure cap vent port if you want to keep the reservoir for a factory look and this usually stops it from happening.
Here's a chart of my IAT's (blue line) on one of my passes this year. This was with a 3.8L Whipple making 24-26 psi, ambient was 82F, no nitrous.
ICT 45F (didn't change until after the pass)
Starting IAT 72F
Peak IAT 90F just over 6 seconds into the run
End IAT 86F
For MAT, it calculates about 20 degrees higher than IAT at these lower temps with ending MAT at 104F.
I use a 7 gallon ice tank with a EWP150 on the tank and the factory pump up front.