Update - Thanks to all the input on here, I tried a number of things including taking the cassette out and verifying if everything was aligned in the splines and re-installed and re-torqued to 40Nm. The noise didn't change or go away so today I was able to get it into the LBS for them to take a look. They checked the derailleurs, cassette, and chain, and said as long as it doesn't sound like that while I'm riding, it should be ok (it doesn't make noise when I'm riding). They did a quick check on my H and L and made a minor adjustment but it made no difference.
While they were checking things out, they noticed my rear wheel was a tiny bit out of true so went ahead and had them to take care of that. Now everything is nice and smooth. They also noticed my ISO-Speed bearing on the seat tube was a little loose and tightened it down. That being loose is probably related to my prior post about the steering tube coming loose from the rough trail I rode a month ago.
Last thing I'll comment is I had a minor creak from my right side on my DA R9100 crank and couldn't figure it out. Even replaced the inner chainring bolts with new shimano correct spec'd bolts and properly torqued them down to 14Nm but the sound was still there. Only happened when I was pushing down with my right foot. After checking and cleaning everything including the pedals and the left crank bolts, re-torquing, i was out of ideas. But I thought of one last thing when I saw that the 4 contact points of the spider arms to the large chainring had some minor friction marks. I decided to put a bit of the chain lube into each junction and gave it a quick wipe down. Sure enough, it silenced the creak. Hopefully that helps someone, or maybe you guys already all knew and I'm just figuring this out now haha.
TLDR: LBS did a check on drivetrain and said it was normal as long as it doesn't make noise when I'm riding it. Fixed a minor creak on my DA crank arms by lubing the spider with chain lube.