Haven't tried that yet personally, my build got put to the side as I was distracted with other things...
The buffer is converting your high impedance guitar signal into a low impedance signal. That high impedance signal coming from your guitar is much more easily effected by electromagnetic interference than the low impedance signal at the output of the buffer.
So...basically, a buffer inside the pedal itself will only help you with rejecting EMI on the output side, not so much on the input side of the pedal.
Or, In English: the wire between your input jack and the footswitch would still act as an antenna. The wire between your footswitch and your output jack would not.
The LFO in this thing are what causes the ticking. The closer your signal-carrying wires get to this, the greater the influence it's magnetic field has on your signal. This follows something of a parabolic curve...when your wire is right up against the magnetic field it has the greatest influence. As your wire moves away from that same magnetic field, it's influence drops in an exponential manner.
...gotta catch myself...English...ahhh...
See, you wanna keep your good, clean and virtuous signal wires away from those damn LFO wires. They're a bad influence. Always a tick tick ticking, I tell you. Nothing but low-life freqs, osc-ill-la-tell you what.
Good news, most of that circuit is on the output side. So an internal buffer will likely do A LOT.