I'm normally not one to suggest features conceived from summat other than mechanical or philosophical conflict, or something not coming from observed metrics (indeed I have no reason to believe we have an extant problem with deletion in betwixt 2 days and 5 days) but this here just feels... extremely unintuitive to me.
We offer 2 days after a question is closed before it is eligible for deletion by users with at least 10,000 reputation. This allows it to stay visible to all parties and allow saner discussion of the merits of a question - it is breathing room for editing and reopening. The main point of this is that not every closure is something that should be deleted, and so salvageable content should be repaired and reopened. Should the question fail to be patched up, though, it reaches the other inevitable end of closure, that of deletion.
We offer 5 days after a question is closed where the question is marked "on hold". This adds a mechanical quirk of putting it in review when edited during this period and also is more welcoming to users - it is an indication of the possibility for editing and reopening. The main point of this is that not every closure is something that should be deleted , and so salvageable content should be repaired and reopening. Should the question fail to be patched up, though, it reaches the other inevitable end of closure, that of deletion.
If the above weren't clear enough, I think it would be better if these time periods were identical. On hold is not a literal grace period, but in expression to users, especially the author of the question, it comes across as one. It's meant to be this sort of "It's not too late" time that indicates that you can, indeed, do something to stick around. And those things that it is indicating to the user that can be done, that's entirely what the actual no-delete grace period exists for.
Neither number is arbitrary in its design, however. 2 days was selected because it's a decent time to house discussion about a question, but it's short enough to help rout out krutz that has no place on the site. This is of more importance on the smaller sites that won't have enough 20,000 reputation users to clear these instantly. 5 days was selected because it's a lengthy period that feels very welcoming and gives a fair chance for a question's defense, but it's strict and settled that it comes to an end.
This comes to how it flows intuitively. On-hold is the visible of the two, due to being the one visible on the question to all people in big letters. The fact that a question can't be deleted within the first 48 hours is, in fact, invisible to anyone who lacks the privileges to vote for deletion and does not yet know this rule (which is documented, to give it credit). All in all it feels awkward that we have a period of time that exists to enable editing/reopening, and a period of time that exists to indicate that editing/reopening is a thing that can be done, and them being different periods of time is what feels awkward. As the on-hold period is the visible of the two, I suggest that the period be 5 days.
This still strikes me about from a weird direction, though, as there's no mechanical issue here or even an anecdotal tale of sorrow of some poor orphan's question being burned to dust, like her home once was, not but two days after she was informed that it was on hold. All the same, the complete lack of intuitive time matching between two concepts which are otherwise completely linked, seems like something that should be fixed. Do you agree?