Bad fuel fouled newish plugs?

[bodega_bladerunner]

Hi everyone, sorry for the long post. Having a small issue on the n55 e30 map on my e82 dct, hoping to get some input.

I am having misfires across all cylinders. About three weeks ago, I took my car to my Indy to get the dme updated since it had never been. This was to help relieve the lurching issue that is common to the DCTs. Prior to dropping my car off, I unfortunately had to stop to get some gas at an unfavorable gas station. My Indy obviously had to uninstall MHD for the update then unlock the DME again, to install MHD again. I get my car back, everything seems to be running great. My Indy reset the clutch adaptations to help resolve the lurching issue, which has about 75% disappeared. However now, what I thought was the clutch slipping at the power levels it once used to hold at, I now realized is misfire.

If I roll on the throttle, no issues.
If I do a quick burst of 3/4 to wide open throttle, no issues.
However, if I have prolonged 3/4 to full throttle, I get misfire. Prolonged being more than 6 to 7 seconds.
I got 1 lean code as I was trying to run down what I thought was the crap gas. Hasn't returned since I filled up fresh.

Valve cover, hpfp, spark plugs and coils were replaced a few thousand mile ago by my Indy chasing a different issue.

So my question and thinking, could the unfavorable e30 I got have gone bad and foul my plugs...all of them? Since the misfire only happens under load, I'd think that definitely points to plugs.
Is there anything else I should try before changing plugs? Switch map to stage 2+ and see how it does?