I honestly can't see patch cables ever being an issue unless they have frayed or oxidized or something. The guitar signal is going through far tinier connections in your pedals than in your cables, and those patch cables are too short to make a diff as far as resistance or capacitance.
I don't agree, and I'll get into that momentarily, but in shorthand there's substantial length and added capacitance between pedals when it's added up, plus EMI and RFI rejection matter, noise matters.
But my pedalboard has a different wrinkle from most anyway so I'll start there.
What you can't see in the picture of my board is what's under the surface lid of the pedalboard. The cable from the instrument input to the wah is about three feet, to provide sufficient clearance for the power cables from the power supply, and to have service length, when I open the lid to change something on the board or work underneath (this board has a hinged surface that acts as a lid, there is an enclosed bottom where the power supply lives, which is great for keeping the innards clean). The cable from the H9 to the board's output is about two feet -- again, so there's sufficient service length when the lid is opened. There's a 10 inch cable from the wah to the buffer.
That's nearly 6 feet feet of cable before we get into the question of the interconnects between the pedals, at least on my board.
The Bay C5 cable I used has a capacitance of 32-ish picofarads per foot. That's about half (or less) of the capacitance of a typical cable. It's also very well shielded, and I have a very, very quiet pedalboard, no hums or buzzes whatsoever. That's important to me, because what I use this board for is my session work.
Aside from the question of noise and hum rejection, if I'd used a typical cable just for these pre-buffer runs, I'd have the equivalent capacitance of a 12 foot run of the C5.
In my setup, it makes an audible difference. I know this because while I was waiting for the C5 to be made when I first got the board, I wired the longer connections up with 3 foot lengths of Mogami. When I swapped the Mogami out for the C5, I noticed less roll-off on the high frequencies. There's an even larger difference when the guitar's volume control comes into play. I use my guitars' volume controls all the time, I hardly ever run them full up. Capacitance that rolls off high end doesn't just come from the pots on the guitar, cable capacitance also loads the pickups. This is most important with the cleaner tones I often use.
I only use a 10 foot cable from the guitar to the pedalboard for the same reason -- cable length matters! I've done an awful lot of experiments to prove to my satisfaction that even a few feet matter.
Sure, I could avoid the cables between the pedalboard inputs, outputs and the pedals, if I simply wanted to plug my guitar cable into the wah each time I use it, and the output cable into the H9.
But one of the things that appeals to me about this pedalboard is that everything's all set up and ready to go, and I plug into the jacks on the board top rear, without having to monkey with the pedals (I don't want to have to think about the many times I plugged a cable into the wrong jack on the back of the H9 before getting this pedalboard, got no audio, and freaked out until realizing, "crap, I put the cable into the wrong jack").
As to your point about the connections inside the pedals themselves, there isn't anything about that I can control. However, I
can control the length of the interconnects, their inherent capacitance, etc.
So I can - and do - minimize the capacitance of the rig by paying attention to the interconnects. Between the various pedals on the board, not including the connections to the inputs and outputs on the board, there are 56 inches of cable in my setup, that's 4 feet, eight inches. At less than half the capacitance of standard cable, however, it's like only having a couple of feet of cable between the pedals in total. Does it matter? As Paul R. Smith says, everything matters, down to the last detail!
NOTE: If you are a high gain player, you don't necessarily want all this high frequency detail, right? Because it can make a high gain amp sound too bright and harsh. But I'd rather make that choice with the amp's EQ or the guitar's EQ, than have it made for me by the cables no matter what I'm doing.
One thing about my rig that might be different from most is that coming out of the pedalboard, I run a cable to a passive splitter box that lets me quickly switch between both of my PRS amps without having to slow down the creative flow by getting up and re-connecting to the other amp. So there's quite a bit of extra cable length in my studio, and that's one reason a good buffer and low capacitance cables before the buffer are essential for what I do.
The bottom line: my board is transparent when the pedals are switched off. The sound is clear, very crisp, and there's no noise. There's no noise generated by the power supply, it doesn't seem to pick up stray EMI or RFI anywhere. This is a good thing, especially so when I use, say, a compressor pedal that will tend to magnify noise generated by the pedals and wiring, etc.
Another strange thing I've found where cable capacitance seems to come into play is that using the volume control with certain cabling, there is an increase in low frequency hum and noise at about 1/3 the volume pot's rotation, until you get about 2/3 up in the rotation. With shorter, lower capacitance cable, this is inaudible or nonexistent. I don't know why exactly this happens, but I've proven it true in my studio, and it seems to be related to cable length, or possibly to the effectiveness of the shielding. Playing clean, it's clearly audible.
So whether I'm set up at my studio, which is usually the case, or at my partner's studio, which is sometimes the case, I'm ready to roll, no noise, get down to business, do the session, and pack it up. I do get a lot of nice compliments on the tone of the guitar regarding my clips here, from guys who seem to care about that, but also from clients. And I get paid very well to do my sessions, so I feel it's my obligation to sound as good as I can, plus it adds to my enjoyment of the creative experience. So it's worth it.