iMac M1 Horizontal Lines Usage Question

My iMac M1 started having the horizontal line issue last month. I am now using an external display which works fine. I did run diagnostics, which doesn't show any issues.

I've read on several boards that this is a known issue, and chatted with Apple Support. They suggested I bring it in, but as it's out of warranty, I can't see paying for a new screen. Other than the screen, the computer works fine. I would just replace it with an M4 Mini, but I currently have 1tb storage on my iMac, and it sticks in my craw to pay $400 more to upgrade from 256 to 1 tb. Especially since I paid so much for my iMac almost three years ago. It appears that I will get little to nothing if I trade it in.

My question is, if I run it with the external monitor, do I risk more damage to the iMac? It does feel hot to the touch on the right side if the screen brightness is up, but I'm leaving it turned down as far as it will go.

Thanks