I would just cut a (small) slot with a dremel or angle grinder and passwords through that, MUCH less chance of chipping the bejeebus out of the enamel and I don’t know about you but, I like having two probes, one “pit” one “protein” the smaller eyelet kit might make getting the probes through it more challenging.
The new thermopro probes I got have much more substantial terminal fittings which would most definitely would NOT fit through that fitting.
No dog in the fight, just an observation. The notch is pretty easy modification. 
My WSM has been “slotted”(thanks Dave) and on the kettle, I really have not seen the need but, I might. Most of the time, my kettle cooks are not as temperature sensitive as many feel is critical so, for forty+ years, I’ve just learned how to pay attention to what I’m doing and fly by the seat of my pants. It’s an art, not a science...entirely. The science is in the basic design and understanding how these two (very different) units operate. When you see how they excel in their own rights, fire management becomes much more predictable and controllable.
I’ve used a thermometer on my kettle once in all my grilling life.
Sorry, that got a little off track but, I’m a believer in “If it ain’t broke...”