I seen some injection molds where the producer has cut the mold where the bait is laying on its side so each half of the mold has the left half or right half of the bait instead of the top or bottom of the bait.. this type of mold could be shot with a twin injector except your color change would not be top and bottom it would be side to side.
Turn the twinjector and you will get top to bottom on these molds.
As far as the hook slotted baits, I shoot some 5"swimbaits with little issue but you can get run over. Wish all the molds with hook slots gave the option to remove the hook slot and shoot, at least for testing.
Wutz-it gives this effect at times, regardless of your plastic temps. Laminate plate is an option if you are willing to put in the time and manipulation required. The "sprue plate" may solve this issue but I have not tried it on my wutz-it molds yet.
Best thing I have found for all molds with the twinjector is to lower your plastic temps.
Jim