FT450 with IGN1A coils grounding questions

As the title says I am using a Fueltech FT450 and 3 Fueltech IGN1A coils on a 3 cylinder 2 stroke. I originally had pins b&d from the coils through seperate wires wired to the buss bar I'm using to expand the negative post of the battery, but was informed that will cause possible interference since i have everything grounded there that says to wire to battery negative and possibly ruin coils. I wasn't given any solutions so I am trying to understand what the correct path is to ground these coils to prevent those possible problems. I have attached two drawings of how I think the wires should be ran to ground the coils properly. The one is a bit cluttered but should be the "whole system" and the second drawing is just the ground wires of the ECU(pin 7 power ground, pin 12 battery negative signal/sensor ground) and the IGN1A coil pin b,c,d.

Thank you in advance for any advice, guidance or clarification,

Scott

The problem with earlier/lower numerical value FTs is that they don't actually do any conditioning for sensor reference - hence pin 12 and 'signal ground' being the same thing. Personally I'd take your first drawing and bus pins 7, 12, and whatever sensors you're trying to keep as clean as possible off of what you label as 'power ground' directly to the battery, ground and have a second bus for the rest of your system - at first glance the rest of it looks correct when dealing with an FT.

Thank you for the reply, it makes me believe i may actually be doing this correctly now.

I've learned more about this since i posted. now i machined a Batt. Neg. Expansion block with multiple holes so i have enough to ground everything that requires to go to batt. negative. I still have the neg. buss bar with a jumper cable to the expansion block that ill use for signal/sensor grounds. Pin B & D from the coils will reach battery negative expansion block through separate properly gauged wire per the manual from Fueltech. Pin 7 & 12 from the ecu will reach the expansion block separately also per the fueltech manual. relay grounds will also reach the expansion block.