Fare code change by gate agents?
 

Anybody have any luck doing this on NW out of Detroit or even LHR or AMS? I've had a Delta agent offer this to me before, and I'm on the "2 round trip in M or higher" challenge right now to get back upto silver, so anything would help.
Any advice?

I suggest purchasing the fare you need. Cause an agent would have to FIM you into your desired new class of service and that is highly unlikely to happen without a valid reason.

Was this a strategy for elite status to request a challenge and and then sorta not really fulfill the challenge fare requirements?

It happens sometimes when you are rebooked due to a cancellation or misconnect, but don't expect it to happen out of the blue.

try asking for different seats, i asked the GA for a different seat on a flight from DTW to NRT, and for some reason she bumped me from Q class to Y class, i ended up getting 1.5 EQMs, but it only happened to me once

How long ago was this? These days they'll just point you to the nearest kiosk where you can do it yourself :p

And yes I have my fare code changed from K to Y by the agent but that's due to a misconnection.

If, by come chance, you DO get you fare code bumped up to a Y due to misconnect, volunteering, etc...

Recommend that you not go back up to an agent looking for that extra exit row, companion seat near/next to you, etc...

"Doubling down" when you get an incidental fare code bump up lately seems to result in the "Hmm!" and reinstatement of your original, lower fare code.