Here's a layout for the Hum-Free(er) Splitter.
Been looking over it several times and I'm pretty sure that it is correct/matches the schematic.
But let me know if you spot any mistakes...
I have added some power filtering that is not on the schematic in case you wonder why there are two extra 100uf and 100nf caps compared to the schematic.
This Splitter design does not have any Phase Reversal and Ground Lift functions though...
BUT! A Ground Lift can be added by inserting a SPST (on/off) or SPDT (on/on) switch between the 1nf cap and the transformer. Meaning: add a switch that breaks the connection between the cap and the transformer (one switch for each of the transformers).
Adding Phase Reversal function is something that I expect would require a bit more circuitry (according to my limited knowledge on the subject)
I see that the Big Shot has a different way of doing the ground lift, then the method that I've been using previously. Gotta try that one. It might be more useful than the one that I've used before (which is totally useless IMO)
Regarding Phase reversal:
The only scenario where I ever have needed a phase reversal switch, is when I have been running two separate pedal chains in parallel going into each their amp.
Then there is a possibility that you come across this problem and would need to correct it.
But when running a single pedal chain into an ABY box, I have never had the need for this, since both amps are receiving exactly the same signal.
There might be amps out there that reverse the phase in their signal path, but that is something I never have come across when running two amps at the same time.
Only when there is a pedal that reverses the phase that is connected to just one of the amps while having both amps active.
Anyway: I'll tro to update the layout with the Ground Lift and Phase Reversal that is featured in the Big Shot diagram, since it is simpler than the other one, that seem to be intended for stereo line signals and not guitar use.