I have wrapped my injector with pipe insulation and that has helped a lot! I didn’t have boiler type when I did it so I used foam hot water pipe insulation which melts when plastisol gets on it but I will replace with fiberglass when the foam wears down a bit. Also, pre-heating the ingectot and tip on a hot plate will make a huge difference. Harbor freight has IR heat sensors for like $12 if you catch them on sale, I usually shoot for between 325-350.

make sure you use a heat stabilizer, not sure if you did but your color is highly effected by the use (or lack there of) stabilizer and NOT overheating.

I have a large injector and I would have a difficult time getting to all those injection ports while the plastic was still hot- good luck with the smaller one.. may just have to take a few shots to get them all.

Id also reccomend that you use a countersink tool to make your injection ports more unirom. That will make for a faster, safer fill of the molds and prevent more spillage. The more plastic you keep in the injector, the longer it stays hot.