Not sure what size egg you have but 225 is unattainable on my XL.... I think the whole "slow and low" thing is taken way to literally.  I cook my ribs and most things between 275 and 325 never paying attention to time, you can usually tell when ribs are done just by looking at them. Remember fattier meats are very forgiving, they will turn out the same with regards to taste and texture smoking at higher temps. I think if you ask most here, they would agree.

 I can't help with advice on the Thermoworks thermometer, I have a Flameboss and it "controls" the temperature with little effort on my behalf. Good luck.

Just out of an abundance of caution, I will clarify that the Smoke is not a temp controller. It is used to monitor your meat and grate temp, but will not help you control these. If you are looking to control put temps, you will have to look at other products (e.g., Smobot, etc.).

The smoke probe wires are not an issue. Let your egg stabilize before putting the protein on and the more you use the egg the better you'll get a controlling temps 

Welcome, and don't worry about a small learning curve with Big Green Eggs.  It's WORTH it!  .  You will absolutely love grilling and smoking on your BGE.  

Strongly agree with what the others said above.

• 225º might be a great temp for offset smokers, but it's just a bad idea on Big Green Eggs.  In an offset smoker, there's a small but brisk fire burning to get that 225º, but in an Egg, where the fire is in the same compartment as the food, the fire has to be so tiny it's just smoldering, you have to cut the air flow off so hard that it's hard to control, and there are NO advantages at all to that low a temp.  Lots of people buy controllers to force their Eggs to do something that is just a bad idea.  A "low and slow" for me on my BGEs is 250º-275º.
• The cables to the probes should not cause air flow problems.  The gasket should be soft enough to curve around them and still seal.  If you see that the dome is open around the cords, take a picture and post it, because something's wrong, and maybe a phot0 would help.
• With some meats, ribs definitely included, internal temp CAN NOT tell you whether the meat is done or not.  Only testing the tenderness will.  With ribs, do that either with the "bend test" (grab the rack with tongs on one end and let the other end hang down and see if the rack bends 90º) or the "toothpick test" (see if a toothpick goes into the meat almost like butter).

One thing I've noticed when using temp probes to monitor temp at the grate level is that location makes a big difference. When using the plate setter, or something similar, it is important to make sure that the temp probe is located over the platesetter and not right by the edge where it has a gap between the plate setter and the edge of the egg. If you locate it here you will notice spikes and drops of temps that will cause you to chase temps and get everything out of wack. 

I go off dome temp and allow the grate temp to be more of a guide, rather than taking the temp literally. I shoot for 260-300 dome temp when doing low and slow in my large. My large likes 280 ish and tends to sit there quite well. I have old crusty gaskets and don't have a problem holding temps with the wires going through. The grate temp tends to be higher than dome, especially early on in the cook. 

You will figure out your egg soon enough. I trust my egg and dome temp, as there can be many more variables in why my probe-based pit temp readings are doing what ever they may do during any given cook. 

Research the "bend test". I'ts an easy guide for getting ribs right. Take pulled pork up to 195 and begin probing every degree or two above that. When your probe, weather it be a tooth pick or an instant read thermo, slides in like a hot knife to butter you're good to pull it off. Same goes for brisket cooks although the temp you want to start checking is a little different and "the cow drives the cook" when it comes to brisket. 200-205 is a typical finished temp on pulled pork. 

Lastly, the daisy wheel is where you'll find it easiest to make temp adjustments when cooking low and slow once everything is going. Changes to the bottom vent will likely end up in way bigger swings than you were shooting for. I usually set my bottom vent to where it typically needs to be on a low and slow once I get a small, efficient, fire going and set my daisy petal openings all the way open. I can adjust down if needed. I typically find myself adjusting down slightly rather than opening things up. 

jtcBoynton said:

Welcome.

The cables are not the reason the temp was not steady.  There may be a slight air leak, but it does not fluctuate and vent adjustments will compensate.

Trying to maintain a 225º temp requires advanced fire management skills.  It is easier to maintain a 240-250º temp. No one will be able to tell the difference in what you cooked at 225º vs 250º (or even up to 300º for that matter).  Next time target 275º and settle for a steady temp 15º either side of that.

Grate temps are also tricky to use.  Grate temps are more unstable than dome temps.  Exact placement on the grate makes a difference. You will get fluctuations in readings even when there may not really be a true heat change within the egg.  You can chase grate temp reading fluctuations that actually cause true heat fluctuations.  The difference between the grate probe and the dome thermometer can be frustrating. Try using the smoke probe in the dome instead of the grate.

This is how I most often use my Smoke.  I rarely put the 'grate' probe on the grate - I stick it through the thermometer hole in the dome.  That way I get remote reading of the dome temp.  I haven't found that the thermocouple wires have created a gap in the dome closure.