Save yourself some coin and link the port rear and the port mid ship together. Use a valve or simple plug like I made for when you don't want the mid ship bag filled.

I suggest this as you aren't gaining any time with the fourth pump since you have the center & IBS chained together. I'm guessing your IBS is 650 and center is at least 400 for a total of 1,050. Your combo on the port side of 750 and I'm guessing the 370 totals 1,120. Thats only a 70 lb variance. In other words, it takes almost the same amount of time to fill center & IBS as it does port rear & mid ship.

I'm venting my bags out same side in rear with no issues. Center & IBS combo where you suggested.