Shucks! I did think about checking the compression but after a few rough morning, I didn't bother. I did even have to pull off the valve cover vanity cover too. I don't have a compression gauge but I could've probably gotten one from AutoZone or Advance Auto Parts. It definitely would've been a good test. I took the X to a spot near the highway that has a quick on-ramp entrance with the intention of seafoaming the thing. I parked up, left the car idling and disconnected the intake tubing just after the MAF. As soon as I did that the 'trans fail safe prog' alert popped up on the dash and it shut off shortly after. I was spritzing in some seafoam into the tube at that point. Scared myself sh!tless to be honest. So I cut the seafoam out of the plan and drove carefully home. It drove OK but shifted abruptly. After shutting it off when pulling in the garage I turned it off and back on again and all was OK. Took a deep breath and just said 'screw it, i'm just changing the oil.' I put in 750ml of the Engine Restore stuff. The difference in the '4,6 or 8' formula is quantity. I filled up with the Rotella T6 5w-40 then buttoned everything up and backed it onto the driveway. I let it idle for a bit to circulate then proceeded to rev it between 2500 and 3000 for 3 minutes. This was per reading this article on troubleshooting valve train/lifter noise:
Toubleshooting BMW Hydraulic Bucket Tappet Problems: Engine Builder
After the 3 minutes I took my foot of the gas and let the idle drop back. Then the bad news. The engine was idling rough and felt like it would stall. I decided to let it run to see if it would 'catch' itself. Never happened. It started to idle rougher and the SES light shot on. I shut it off immediately. I gave it a minute and cranked it back - perfectly normal albeit not as smooth. So I took it out for a spin around the block. No issues, idle still not as smooth as prior to my oil change. I then took it out on the freeway, really laying into it, revving to about 6K on two on ramp entrances. It certainly felt more sure footed.
Brought it back home and listened to the idle with my ear to the valve cover. It was noticeably quieter and idled as smooth as before the oil change.
So after two scares in my morning, both likely self-induced, I was happy she was running as good as she was. I'll report back on how it feels on the next fill up. I know numbers would have been better but i'm pretty in tune with the feel of the vehicle and its performance so hopefully that means something.
Thanks for the advice JCL. In hindsight, wish I read it and considered it earlier.