I (seemingly) solved it. Open up the laptop and tighten as many of the Phillips screws that attach the keyboard to the input cover as possible (some of the screws are blocked by components that overlap them). I found that all such screws had loosened considerably. Just be careful not to strip the heads - although Framework does sell a full set of replacements for $5 if you do.
One additional bonus is the keyboard feel (which seemed to become more mushy with age) will also be improved. Presumably, following the full steps here to access all such screws would provide even better results. I might try adding thread lock to make the fix last longer (permanently?).
Been stuck in the same boat as you all for many months - the delete key started working only intermittently, and then progressed to being entirely dysfunctional. At the start, applying pressure seemed to help but this eventually did not help. I reached out to support and the phenomenon was written off as “customer-induced” due to fall damage to the upper right corner of the laptop. This solution immediately rescued the functionality of my delete key, and fixed some of the “mushiness” in the keys that seemingly developed over the lifetime of the laptop. I am curious exactly how long it may take for the screws to loosen once more, but for now the issue seems resolved.