I would consider plugs a mandatory thing, with all the issues I've seen on the facebooks and some of the forums. A lot of weird nuance issues can come about from corrosion or water intrustion into the plugs and they are all, from my understanding, are direct feeds back to the ecu so you risk a bigger issue of potentially shorting out and the ecu acting as the fuse. I would say you've just been lucky bc you are in a dry state. A lot of the issues I have seen have been from a northern wetter/snowy state. For 100% protection and longveity from potential issues and corrosion should you ever need to go back to stock, dieelectric grease and plugs should be mandatory.
If you have the the time, the extra cash just sitting and potentially not using a proverbial "condom" over the plugs, I would use electronic cleaner to jet them clean, let it dry, pack in some DE grease, and then cap them with a plug kit.
OR
Pull the emissions harenss away from the ecu (I think it's the most driver side plug at ECU - someone can fact check me), and then get ONE single cap for that that I also think SHIBBY makes a kit for (both ecu harness and open ecu plug).
