In the RMA process I would let Intel know that you're a small business owner and that being without the processor for any period of time means thousands of dollars in losses. See if they will be willing to compensate you for a purchase instead of an RMA replacement. Or willing to send you a replacement prior to you sending the processor in for RMA.
The 12th generation processors are presumably compatible with your motherboard. They also have really decent failure rates based on the Puget Systems data. The second best all around of anything Intel or AMD since Intel 10th generation:
https://www.tomshardware.com/pc-com...e-rate-data-cites-conservative-power-settings
Newegg is currently selling the 12900KF new for $326:
https://www.newegg.com/intel-core-i9-12900kf-core-i9-12th-gen/p/N82E16819118341
In general though I think a couple of additional important lessons to "learn" from this are: always have a backup on hand ready to plug in at a moments notice, and maybe do your gaming intensive work on a separate computer from your business work? I would guess that your business doesn't need anything near the processing or graphics power of your gaming. I'm not trying to be preachy or critical, but you never know what's going to happen to your one and only computer, and making a living is a heck of a lot more important than playing games (unless this is actually part of the draw for your cafe).