I can weigh in on this. I to contemplated replacing the airtemp gauge with an oil temp gauge. The cost of both the in dash gauge and the dip stick is the same. For two hours labor, they can install an oil temp sensor in the oil pan for read out in the dash. That gives you a continual temp that is very useful, IMO. To tap the oil line before or after the oil cooler, which seems to be the dealership less relevant response, doesn't cut it.
People say that these gauges are accurate but that is an issue of faith as I asked about calibration and the parts guy's eyes glazed over. At least it will give you relative temps if not accurate temps.
Now that I have the dip stick, I would not buy it again. On my CUSE, to lean the bike slightly at a stop sign, activate the button and read the temp is scary. The bike is too heavy, center of gravity too high, and the readout is recessed in such a way that it is difficult to read while sitting on the bike. I can read it only when I am off the bike. I had really wanted to read it while riding. This 110 runs hot so an on going oil temp readout is important to me. This dip stick misses the mark.
If I had to do it again, I would pay the extra money and install it in the dash with the sensor in the pan.
Take your best shot. Good luck.