I found some DVM modules at Mouser made by Murata, that are loop powered by the input voltage and current. They would eliminate the power supply circuit. I need to investigate that a bit more though.
I will admit the whole V- V+ and floating ground vs earth ground thing has me a bit confused. Also +S is a giant WTF. But its only a matter of time before it starts to sink in. Right now the connector J1 has two number threes but it won't be hard to sort out once I pick a display. Let me know if you see anything I messed up.
The thing with lab power supplies is that you can dial the output down to 0V. So you can't really power the voltmeter with the output voltage as it will cut-out at some point as you dial down. Also, ammeter modules include their own shunt (another low value resistor like R2) which will lower the output by the
burden voltage.
In the case of the E3610A R2=0.1ohm, therefore a 1A current will produce 100mV and a reading of 1000 on a 0-200mV full-scale 3-1/2 digit voltmeter.
In the case of the E3611A R2=0.2ohm, therefore a 1A current will produce 200mV but to use the same voltmeter, R11+R12 (10K+10K) divider is used to cut that in half.
So the purpose of the R11+R12 divider is to adapt the shunt to the voltmeter selected (as ammeters are just voltmeters measuring shunts).
Same for R18+R17; to adapt the output voltage range to the voltmeter selected (showing the output voltage reading to the user).
Yes, I saw the pin3 referenced twice mistake too.
Now, onto a critique of your schematic...
Wires should go from symbol pin to symbol pin; don't just end wires as it will fail DRC and will be a mess going forward into the PCB layout stage. Unused pins should have the "x" (no connection) flag attached (see right icon bar).
Don't mimic switches with wires; there are many switch symbols. Search under the "Switch" category in the Add symbol popup or search for "SPST", "DPDT", etc. in the search bar. It's a big haystack. For example, if you can't find one like "SP7T", open "SW_SP3T", edit it, create/save-as to your own library for future projects.
I find HPs schematic hard to follow with all the long wires going between sub-circuits. I like to isolate bite-sized parts (but not go too microscopic) and connect them through global or local labels. See what others have done on the Internet to get a feel for it.
Use the power symbols; Add symbol from the "Power" category or ⏚ on right icon bar. Don't just end wires with "+12V" or "[+S]" text. If you have two rails that are the same voltage but should be isolated, then select a different power symbol (eg. "+5V", "+5VD"). Also, google "kicad PWR_FLAG".
[Not in yours but] most schematic readers expect inputs on the left, outputs on the right. Similarly, positive power is ordered above GND and negative power below GND.
Once you think you're done with the schematic,
a. either manually change all reference designators (eg. "Q?", "U?") to match HPs schematic or use the Annotate Schematic popup to (randomly) assign them for you.
b. Then run rules check via Electrical Rules Checker popup.
c. Then call Assign Footprints popup to select footprints for each symbol.
d. Only then you can proceed to the PCB layout editor.
Attached, you will find my take on a re-written version of the the E3610A.
Your style may be different and that's okay.a. I've purposely cleared all reference designators to "?" and kept the default for the symbol value field to show the generic symbol chosen. I also re-organized and separated the sub-circuits into functional chunks which I believe are easier to read/understand.
b. Op amp GND (▽) and "+S" label are attached at the positive output post.
c. I use the protective earth symbol for the 3rd plug prong which is isolated from op amp GND above. Unfortunately, the stupid plug symbol has a ⏚ which is confusing with PE symbol attached to the pin. I/you should just make your own library version without the ⏚ lineart.
d. +5V in the original isn't really used as a power rail. It's really a stable +5V reference so I made it a label instead of using a power symbol.
e. Notice the display power uses +5VD/GNDD which is isolated from any other rail.
f. I've substituted a TL431+2*10K for the LM336.
g. I've used connectors for J1 and the output posts. As far as I'm aware, you can't split a single connector; distributing the pins over the schematic like HP did for J1. It must be a single n-way connector with wires or labels attached.
That's all for now.