We have to some correction of water flow and temperature of water with mold temperature control unit, but it is extra cost and setting it to optimum level with minimum extra energy cost is critical and time consuming.
At corners, forces are in 3d for shrinkage, some corners require the design to be compromised or if not to compromise an another pre made filler plastic insert to added while molding and/or extra cooling at corners externally and/or by giving feeding material (hot), ie an extra gate point with, and its direction of feeding material, towards the shrink pulling.
Why all this, because when pressure is applied to a semi fluid , semi liquid, it will solidify / crystallize, faster– in this process, latent heat of solidification and heat energy will also be give out in fraction of second, so I try to call it non-linear flow and sunami condition, so don’t worry, try to give optimized solution.
When 10 dia hole is there, flow is to be maintained (by extra energy (pump positive drive one)), so try to take the flow natural ie parallel to the surface of the component. and at critical juncture, ie corners, another cooler water ckt– a jacket with routed piping is the type is better for insert of cavity and core, though it may (later on) increase maintenance. But definitely cut cost on process and cooling efficiency, done to the maximum with conventional machining (though doing this routing piping in jacket type cooling, time of matching will increase of mold making and onetime cost, but you save on process later – savings will be proportional to quantity.) So see the problems first or define the process first, over view holistically and give the best of yours.
Now the mound has to intelligent electronic – some sensor (rtd mini) to know critical areas, and use in early warning system and control the mold thermal unit (can save some energy.)
Better if we had some non-conventional machining process, which could drill (edm) holes parallel to the surface section in that instance consideration, then the goal will be achieved to the maximum efficiency, may not be ideal, but will definite improve the energy balance condition in most cases.
I am comparing the hole making of written (German manufacturer), to dig hole across roads by going “around underneath” without digging across, something of that sort would have been there in edm it would be helpful.
Though there is some German technology is available for mold making through real time, to build by material deposition and includes holes (cooling). (Costly and time consuming but available and practicable.)
That’s all from me. I am finished, I hope I have not triggered a debate, I spoke in general, it has to judge to situation to situation, I think we all are telling you books, physics and practicals and experiences, I think that’s enough for you, isn’t it? I think I am up will all until I can think differently and may be over your more thinking over comments and ideas, opinions.