Required reading:
The state of the underhanded tag
Has underhanded been getting too much like code-trolling?
The state of the popularity contest tag
And the motivation for this discussion of course: Rig The Lottery, but Don't Get Caught
There is a discussion in the comments of the last link about policy adjacent to underhanded, code-trolling, and the post is tagged obfuscation, presumably because the OP couldn't tag it underhanded.
The current policy is clear. underhanded and code-trolling are both banned from the site, and the post shouldn't be allowed. This was vocally supported by at least one member, and pointed out as a matter of fact by the moderation team.
On the other hand, it is quite clear that the post in question, were it to be allowed to stand, as well as the submissions, are good additions to the site. The post reached HNQ, and the vote count of sumbissions and the post itself show that most members find it as such. Downvotes were explained by the downvoter as being policy-based, and not quality-based.
To add to this argument, the last time this was discussed 9 years ago, this comment was made, and appears especially relevant:
Many existing underhanded questions deserve to be revived due to their ingenuity. It is a pity that one single answer here was accepted and referred to as “Community consensus” that was used to justify the butchering of this category.
– Andreï V. Kostyrka Commented Nov 21, 2016 at 11:36
It is my personal view that the community culture that created code-trolling and made underhanded into a mirror of it has since disappeared. I believe that code-trolling would not be as popular as it was then, but I do not think it would be a good idea to reinstate it (if you believe the opposite, feel free to create an additional policy discussion post about this). However, I believe that underhanded can be rehabilitated as shown in the linked post, hence this policy disccussion.
I see 3 options, for which I will create answers for everyone to vote on in order to avoid a repeat of 9 years ago. Feel free to add other options if you believe they are relevant.
Option 1: underhanded stays banned. Nothing changes, the current situation works well and the linked post, while good, cannot stand because it is against the rules (or, it should be locked as historic).
Option 2: underhanded is rehabilitated and can be used like any other tag. Low-quality questions using it are still closed as low quality, but a challenge simply being underhanded is not enough of a reason to close it.
Option 3: underhanded is rehabilitated, but with additional safeguards that place a heavy burden on the poster to make sure the post is a good fit before being posted. I propose mandating use of the sandbox for all underhanded challenges, and such a challenge must have at least a net score of +2 in the sandbox to be allowed on main. Not using the sandbox prior to posting is grounds for immediate removal regardless of quality.
Both option 2 and 3 imply unlocking relevant historic challenges that were locked when the previous policy was enacted.