actually the way that i routed my ts probe was kind of a pain in the arse. i did it the same on my vmc-20 when i did probes on that machine just recently. the install went without issue, but maybe it could be easier another way. what i do like about having it routed in conduit back behind the y-axis is that its a pretty clean looking install. I then run the conduit up where the 4x connector is. i just used an electricians knock-out punch (see harbor freight or similar) to make a new hole for the conduit fitting. remember that you have to allow for full travel of the table, and also you have to make sure it will never bind.
if you mount the tool setter probe on the right side of the table, i'm pretty sure the universe will stop expanding sooner than expected leading to the next big bang in our lifetime.. do you want that on your conscience?
(if you use a vh-65 or similar 4th axis, usually they're on the right side like mine is so its in the way) my opinion on this is go thru the probe install in the most professional and clean way possible. you want to do it once and not have to fight it ever. I still run the check probe (UT, 3) every day to make sure there isn't some problem. you'll be putting the 4x on and off all the time, so why make that hard on yourself? just go through the trouble on the probes.
I'd highly recommend conduit anyhow seeing that if the wires get damaged you may have a very serious machine crash for a number or reasons. the conduit noted in the renishaw manuals is nice, but it isn't available in the usa. I just used 3/4" or 1/2" metal reinforced liquid-tight from home depot. you'll have to make a way to connect the conduit up to the mp probe. I used a flare fitting to npt because the thread is correct. you could also make a fitting of course doing some thread milling. that'd be a lot cleaner and probably cheaper.
my mi-12 box sits on top of the control cabinet, on the right side of the machine. its best to route all wires up into the wire routing on top of the enclosure because that goes right into the ctrl cabinet on the right side. its easy.
best of luck