Shifted about as requested, not yet looked into slots around the reference,
Now both the resistor array and input mux are far enough away from variable heat sources that the thermal difference is too small for me to worry about further, but I am open to mixing things up.
Capacitors where mis-sized for a higher voltage, picked the most common footprint for 100uF >35V and ran with that for the lot of them, half of them should be 47uF which could get away with smaller, but I don't really see a need for it.
the +-15V caps being nearer to point of load is already mostly done, the biggest load is the reference, then the input buffer, everything else of significance is on the analog +-15V rail, where the largest loads are the second integrator op amp and the slope amp.
The main power traces right now are on the back of the PCB in 0.8mm thick traces, at the current levels involved the varience over the largest load difference should account to about 300uV of DC shift on the supply rails, everything is locally decoupled,
Its the AC influences I cannot fully control for,
For the external reference, you say 2 rows of 5 pins, I assume something like below?
Or skip the sense thought and instead its just for contact reliability
+15V +15V
-15V -15V
GND GND
-Ref -Ref_sense
+Ref +Ref_sense
If there is a popular reference module e.g. the KX LTZ1000, and someone can give me its pinout and connector dimensions I could just space it out to make it plug and play.
the slope input trace is very overkill, but having it there makes the math easier, so unless it hurts something, I will leave it be, as the ground would be there either way to soak up some of the noise from where it passes through. There is a fair bit of energy every time the slope output moves, and that would couple in too easily otherwise.
U16 confuses me a little, where R10 and R7 are meant to connect, and assuming that only U16's reference is the same as the main PCB
Edit: Ok, just an inverter, so to 2 different inputs, What is pad 2 for?